Whether you're a hardcore gamer or more of a casual fan, it isn't that hard to think of which attributes make playing video games so enjoyable. A good visual art style is something that can grab you right away, and a compelling story helps to keep you interested all the way through, but clean and consistent gameplay may be the most important aspect of all. Still, there is one important feature that we haven't mentioned yet. If you read the title of this list, then you know: it's the secrets!

Whether it's a secret character that you can only play as by beating the game on the hardest difficulty, or secret weapons that require some kind of cheat code to unlock, secrets are one of the coolest and entertaining aspects of video games that just keeps us coming back for more. Beyond all the unlockable characters and infinite rocket launchers, however, are the secret areas. Nothing can blow the mind of a gamer more than having played through their favorite game for the 100th time before realizing that there's an entire section of the game that they didn't even know about!

Believe it or not, missing out on entire segments of your favorite games happens a lot more often than you may realize. Think we're bluffing? Then check out these 18 Secret Video Game Areas You Didn’t Know Existed, and see for yourself!

Aliens, Ruins, and Hell (Tony Hawk's Underground 2)

Tony skates in hell in Tony Hawk's Underground 2

The Tony Hawk's Pro Skater series is well known for it's wide-range of crazy levels, particularly the secret bonus stages that are usually unlocked after beating the game. Tony Hawk's Pro Skater 2 had the fantastical "Skate Heaven", and Tony Hawk's Underground had "Hotter Than Hell" (a level featuring the rock band KISS), but "Triangle" in Tony Hawk's Underground 2 is on a whole other level.

An obvious reference to the mythical, real-life Bermuda Triangle, the Triangle may not seem like much at first, but there's more to it than meets the eye. After activating the missiles on the wrecked Apache helicopter, you blow a part of the alien away, revealing a hidden alien base. If you're investigative enough here, you can activate a portal which will send you to what seems to be Aztec ruins. Finally, if you curse all of the monkey god idols, then it will open a portal to — you guessed it — Hell!

With not one, but three secret areas to discover in total, each requiring a different set of tasks to reveal, Tony Hawk's Underground 2 has arguably the coolest bonus level in the entire series. (Did we mention Hell?)

The Castle Roof (Super Mario 64)

Princess Peach's castle in Super Mario 64

When Super Mario 64 came out alongside the Nintendo 64 back in 1996, it set the standard for what a great 3D platformer should be capable of. Making his debut in three-dimensions, Mario is tasked with finding a number of Power Stars scattered around Princess Peach's castle in order to make his way to Bowser, free the Princess, and release the castle from the evil Koopa King's clutches.

Gamers who grew up playing can remember going through the various levels and missions throughout the castle, collecting stars from worlds filled with haunted mansions, boiling lava, and enough of Bowser's minions to make a plumber's head spin. While most who played the game can recall making their way to the top of the castle in order to defeat the giant turtle himself, many are actually unaware about what secrets lie ahead if you're actually able to collect all 120 stars found in the game.

If you do manage to collect every star, the cannons in the courtyard open up, allowing you to shoot up to the normally inaccessible castle rooftop. Up there, you'll find find a familiar green friend (not Luigi), who gives Mario 100 lives and a special jump ability!

Reptile Pit (Mortal Kombat)

Mortal Kombat Reptile

After Street Fighter II was released to arcades in 1991 and met with great success, it was followed by a plethora of knock-offs and clones which tried its best to emulate the groundbreaking fighting game. It was just one year later when arcade-enthusiasts were greeted with a new type of fighting game to rival Street Fighter. We are of course talking about Mortal Kombat.

The first thing that caught the attention of arcade-goers who stumbled upon this new title was just how violent the game was, with more digitized blood and gore than most kids had ever seen before. Another thing that stood out was the cryptic hints given seemingly at random by a green-cloaked ninja, such as "Look to La Luna" and "Blocking will get you nowhere".

If players were able to figure out what all of these riddles meant, and applied them in-game, they would have the chance to meet-up with the game's secret character, Reptile, who is fought at the bottom of the pit level. Imagine the look on the face of the player who first accomplished this, dropping into the spiked pit area which was usually only reserved for players getting impaled!

 The Painted World of Ariamis (Dark Souls)

Dark Souls The Painted World of Ariamis

In a time when video games had started becoming oversaturated with constant hand-holding, overly-generous saving systems, and difficulty levels that hardly gave players a challenge; the Dark Souls series came along to remind people how satisfying it can be to overcome challenging obstacles in games.

Hearkening back to an older era of games, Dark Souls uses a combination of nostalgic yet frustrating elements from games of days past, such as unforgiving game over punishments, and open-worlds that give hardly any indication of where you need to go. Because of this, there's many areas that players may miss out on during their first, second, or even third playthroughs of the game.

While accessing new areas in the game usually involve simply finding a key, or making your way past a certain obstacle, the Painted World of Ariamis is a bit different. First you have to pick up an item which requires you to return to the very beginning of the game, then you must examine an otherwise inconspicuous painting. After this, you'll find yourself in the drawing itself, a snowy world complete with treasures, and a secret boss!

Special Zone (Super Mario World)

Super Mario World Special Zone

A lot of you are probably scratching your heads right now and thinking, "Is there really an area in Super Mario World that I don't know about?" As it turns out, even for those that have beaten the classic Super Nintendo title multiple times, there's a good chance they still haven't come close to discovering every area in the game.

It's well-known that you have to use a "secret exit" in the Forest of Illusion, or else you'll be running around it in circles forever. This isn't the only alternate route in the game however, with levels all over the map containing secondary routes which lead to Star Road. For those of you wondering what "Star Road" is, we've only just begun!

Star Road is a hidden area which contains bonus levels and gives Mario shortcuts around the overworld. However, if players snoop around enough, they can find another secret exit in one of the Star Road levels which leads them to an even MORE secret area called the Special Zone (we know, it's starting to feel like Inception). Once here, players are rewarded with the hardest levels in the game, all titled with outdated slang like "Mondo" and "Tubular".

Golden Island (007 GoldenEye N64)

Goldeneye 007 Golden Dam Island

Although it may seem dated now, both in terms of its primitive graphics and less than perfect gameplay, there was a time when GoldenEye for the N64 was the game everyone had to get, and it's still often cited by many as one of the greatest games of all time. Not only is it one of the rare examples of a movie-based game garnering critical and commercial success, it was also one of the very first FPS games to introduce a competitive multiplayer mode.

Considering GoldenEye was developed by the legendary company Rare (sadly, a shell of its former self nowadays), it really shouldn't have come as a surprise that the game would be a hit. Though the game is 20 years old now, and it would seem that there would be nothing left to discover, never underestimate gamers.

Using a hacked Gameshark code, players were able to finally visit a mysterious little island in the distance on the Dam level, revealing a whole unused section of the game which Bond would have visited via a boat. This ended up being too challenging to program, and was scrapped, with the physical island left behind to intrigue players to its purpose.

The Secret Garden (Shadow of the Colossus)

Shadow of the Colossus Secret Garden 2

Shadow of the Colossus was one of those games that introduced a really fun and groundbreaking concept, while also managing to deliver a high-quality gameplay experience. Before this came out, just how many games have consisted of a horse-riding wanderer traversing a large open-world, with the goal of finding and killing sixteen gigantic creatures? We're pretty sure the answer is none.

As expected, with a world map as large as this, there's lots of potential for unseen areas of the game that players can easily miss while making their way to the next target. After defeating each colossus, the player must return to the large Shrine introduced at the start of the game. What many people don't know, however, is that if your stamina is upgraded enough by the end of the game, you can climb up the shine and take a very specific and arduous path, one which leads to a place known as the Secret Garden.

There isn't really too much to do here, besides eating the fruit which will drain your stamina and strength, but it's amusing to think there was a hidden area right under (or above?) our noses the entire time.

King Arthur's Knights Fighting a Rat (Fallout 2)

Fallout 2 King Arthur's Knights Fighting a Rat

When people hear the word "Fallout" today, they usually think of a role-playing FPS game that plays very similarly to the Elder Scrolls series. But there was a time (before Bethesda), when the games in the Fallout series played very differently. One of the coolest mechanics seen in Fallout 2, for instance, was the chance of running into a Special Encounter during travel.

While traveling often resulted in running into normal enemy encounters, once in a while, the player would instead experience a rare event. Two of these Special Encounters happen to be references to Monty Python and the Holy Grail, with "A man guarding a bridge" referencing the part in the film where King Arthur and his men must answer three riddles, and another where you get to meet the King and knights in person.

In the game's data, however, lies a third Monty Python reference that remained undiscovered for a time due to a glitch which made the encounter impossible to occur. But if patched back into the game, players will stumble upon King Arthur and his Knights struggling to fight off a single rat near a cave, mirroring their battle with a vicious rabbit in the movie.

Ghostly Room (Call of Duty: Finest Hour)

Call of Duty Finest Hour Ghostly Room

The Call of Duty series is known for having its fair share of elaborate secrets hidden in specific levels (usually in the modes containing zombies), but perhaps the most secretive and disturbing of all would probably have to be the Ghostly Room in Call of Duty: Finest Hour. It also goes to show that the series has been doing pretty absurd stuff for a while now.

To discover this secret area, the player must first come across a seemingly unopenable door in the Underground Passage level. They must then throw two grenades at the door, walk up to it and use the action button (even though no action command appears), and then throw one more grenade at it to blow it open. Inside is a long narrow tunnel which leads to the Ghostly Room.

The room is mostly just an aesthetic easter egg, with: a bunch of creepy pictures on the walls, floating candles, a tiny Sherman tank, a ghost-boy in a crib, and an over-sized rat in a cage. Beyond this, are two teddy bears which can be used as explosive weapons, though more for comedic purposes than practical.

Minecraft Area (Borderlands 2)

Borderlands 2 Minecraft

Gearbox, the developer of Borderlands, described the hit series as a "role-playing shooter", due to its characteristics stemming from both genres. The debut title had players take the role of one of the violent fortune hunters visiting an alien planet in order to find a treasure-vault that is said to only open once every 200 years. With its cel shaded-style visuals, action-packed gameplay, and interesting — if not psychotic — array of characters, the game was a huge hit.

Then the sequel came out, and, well, people loved that too! The only thing that really drew criticism was the use of very-dated meme references throughout the games. They may not have been dated at the time, but even when it came out, people knew it was just a matter of time before many of the "cool easter eggs" became cringe-inducing.

There was one particular in-game secret, however, which is just as cool now as it was back then. We're talking of course about the Minecraft area. This isn't just a small reference, but an entire section, complete with breakable blocks, and creeper enemies!

Duck Race (Shenmue II)

Shenmue II Duck Race

Ah, Shenmue. A tragic example of an ambitious and revolutionary game title failing to achieve the success that it deserved. Originally released for the Dreamcast in Japan in 1999, Shenmue boasted a number of innovative game mechanics, including: a day-and-night system, variable weather effects, and a living world whose inhabitants go about their daily routines regardless if the player interacts with them or not.

The game centers around teenage martial artist Ryo Hazuki, who is investigating the murder of his father. When not focused on the main goal, players are able to enjoy a number of mini-games, including throwing darts and playing older Sega games at the arcade. The sequel brought in even more bonus content, with one odd event in particular, the Duck Race.

To unlock this event, the player must accomplish numerous challenges at the Pine Game Arcade, including obtaining both the Bronze and Silver medals. Then, after beating Izumi Takano in a street fight (one of the hardest fights in the game), talk to her again, and she'll take you to the secret Duck Race mini-game. That sure seems like a lot of work just to race fowl!

Warden Sharp's Secret Room (Batman: Arkham Asylum)

Batman Arkham Asylum Warden's Secret Room

Video game adaptations of comic book characters have had a rocky history in the past (think Superman 64), but all of that seemed to change when Batman: Arkham Asylum was released in 2009. Not only did the game have detailed visuals, a compelling story, and a superb voice cast, but it also utilized gameplay elements which made players feel like they were truly in the boots of their favorite superhero.

One of the Dark Knight's many nicknames happens to be the World's Greatest Detective (sorry Sherlock), and true to his name, Arkham Asylum makes full use of Batman's detective capabilities, by having the player search for clues in order to progress through much of the game. There was one secret, however, that was so difficult that the developers decided to reveal it months after the game was released, so that it didn't get overlooked.

With no in-game hint to do so, players were told to blow up a certain section of Quincy Sharp's office, revealing a secret room that contains plans for Arkham City, where the sequel would eventually take place. Hey, even detectives need help sometimes!

DX2 Wrap Party (Deus Ex: Invisible War)

Deus Ex Invisible War Wrap Party

While most games tend to have a straightforward storyline which is told in pieces as the player progresses throughout the game, and wraps up with a singular ending, others have decided that one ending simply isn't enough. Deus Ex: Invisible War, of course, takes the multiple endings route, letting the player's actions throughout the game affect the end result. There are four standard endings, one of which includes a complete Illuminati take over, while the other focuses on the result of nuclear war. But forget about all that, because there's actually a secret 5th ending.

All you have to do is take a random flag to a very particular bathroom, and then flush the toilet inside, and you'll be taken to what the game calls the "real" endgame. After this very specific set of actions, you'll be teleported to a nightclub, where various characters are dancing around and having a generally good time. Now if only all games about war had an ending as nice as this.

Zelda A Link to the Past Chris Houlihan Room

For this next one, we're going back to the Super Nintendo to cover what many people consider to be the best SNES game of all time. If you're a big-time Zelda fan, and you're wondering how on Earth you could have missed a room in one of your favorite games, then don't worry— it just means that you're good at not breaking things.

The Chris Houlihan Room isn't an area that is meant to be visited normally, but rather, it's a fail-safe room that prevents the game from crashing whenever it can't determine which room it's supposed to send Link to. This means that this area can only be reached from causing a specific glitch, of which there are five different methods to accomplish.

If you're confused about the name, it's named after a fan who won a contest held by Nintendo Power in 1990, in which the winner was to have their name programmed in a future NES title. This isn't too bad of a replacement prize!

Secret FBI Cave Bunker (Grand Theft Auto V)

Player inside of a secret GTA 5 military bunker with an industrial metal look.

With their notoriously huge world maps, the Grand Theft Auto series has always been filled to the brim with secret areas and easter eggs that would take hundreds of hours of gameplay to come close to discovering in their entirety. In no entry to this series is this more accurate than the expansive GTA V, which makes references to aliens, Bigfoot, and even Breaking Bad. What we're focusing on, however, is one of the most elusive areas in the entire game, and that's because it involves the FBI.

Firstly, you have to make your way to the Pacific Ocean by any type of water vehicle, before seeking out one specific tiny island out in the middle of the water. You'll have to find an inconspicuous piece of land where two trees are standing next to each other. If you've found the right spot, then walking into one of the trees will automatically transport you to a strange room.

You may be wondering where you are, but turning around will answer that very quickly, as you see dozens of armed men. You're in a Secret Underground Base, full of agents, vehicles, and plenty of suspicious activity.

Cake Room (Portal)

Portal Cake Room

"The cake is a lie." Chances are, you're either sighing or smiling with glee, as this is one of the most quoted lines in video game history. Thankfully, the game that it's attributed to totally deserves it, since Portal is one of the coolest and most innovative titles to come out over the past decade. A 3D platformer that focuses on using a portal gun to solve puzzles may seem like a simple concept, but we're lucky that Valve was the one to actually go ahead and execute this idea to virtual perfection.

So anyway, about that cake. As it turns out, despite all we've heard over the years, the cake in fact is not a lie. Sure, at the end of the game, you get a quick glimpse of the moist chocolatey treat that you're promised throughout the test run, but did you know you can actually enter the cake room yourself?

To do this you're required to make a lot of tricky portal shots, precise jumps, and even a bit of glitching, but if done correctly, you'll find yourself in the actual cake room. And what's better, your buddy the Companion Cube is there too!

Romero's Head (Doom II)

Doom II Romero's Head

For the penultimate entry on this list, we're going old school with Doom II. Doom wasn't the first first-person shooter (Wolfenstein 3D had been released just a year prior), but it is the game that popularized the genre. It was so influential in fact, that before the term FPS was even used, people instead called games of the same genre "Doom clones".

This secret area happens to be located in the final level of Doom II, during the ending boss fight with Icon of Sin. Normally, in order to damage this boss, you're required to shoot a rocket through the hole in its head, but you don't actually get to see what exactly it is you're damaging. Could it be its brain? Or perhaps some smaller demon inside of it? Nope, it's John Romero's head.

Normally designed as an in-joke, players can actually pass through the monster's face by either using a no-clip cheat, or a very precise glitch jump. Once inside, they'll see that the hidden target they're dealing damage to is actually the pixelated head of Doom developer and co-creator John Romero on a bloody pike. That's one hell of a way to make a cameo!

Gabe Newell Room (Half-Life)

Half Life Gabe Newell Room

Finally, we're onto the final secret area, and coincidentally, it also features a game developer making a sort of "cameo". This time we're talking about the legendary Gabe Newell, the co-creator and current president of Valve. John Romero may have set a precedence for creepy in-game cameos, but Newell takes this to a whole other level. And where else, but in Valve's classic: Half-Life.

Once again, this is a secret area that can only be reached by using a no-clipping cheat. First you must get to Chapter 3: Unforseen Consequences, then you must clip through the floor near the bottom of the room with the giant elevator. Once you see a black cube, keep going towards it until you're inside. Then, take a deep breath and turn on your flashlight, because you're in the Gabe Newell Room.

We apologize in advance for any trauma this may have caused you, but yes, you're standing in a room with walls, a floor, and a ceiling that are all completely textured with Gabe Newell's face. Perhaps this one would have been best left unknown.

It's crazy how you can play a game over and over and still have some secrets leftover to discover. Were you surprised by any of these secret areas? Do you know of any others? Let us know in the comments!