Full Customization is Needed in Diablo 4
There's a fair bit of customization in Diablo when it comes to the loot collected, but there are still elements that can't be controlled. This leaves the game a little at odds in comparison to to even some of the classic RPG world, let alone modern titles. Indeed, Diablo 3 does feel a little limited when it comes to choosing character designs, and Diablo 4 could do with an upgrade in that regard.
Full visual customization of the characters would be great. Not only would it allow players to really make their playable character their own, but it could also add to more variety in the multiplayer scene, with different takes on each character making multiplayer team-ups feel unique.
This should follow through to character builds as well. A more varied skill tree could allow players to have different options on how to play heroes, and being able to create characters that work well as a team in different ways could potentially add even more longevity.
Flexibility of play in Diablo 4
A lot has changed in video games since Diablo 3 first announced, and the level of restriction placed on the game at launch would be even more criticized in the modern day. Although the stuttering start to Diablo 3's life in the wild may have been forgotten about (aside from those few who still get chills at the mere mention of Error 37), it's fair to say that the limited options available upon release would not fly today.
Something that will be requested for Diablo 4 is cross play, should the title launch at the same time for consoles and PC. Allowing players to team up across different devices has been one of the key improvements that gaming has seen in recent years, no longer forcing groups of friends to have to own the same system to still play together. If Nintendo and Microsoft can work out Minecraft cross play, then surely Blizzard can do similar.
It's not just modern advancements that could make Diablo 4 a bastion of accessibility, either. Diablo 4 should resist the temptation of always-online, for instance, to maintain a flexibility for those who would like offline play. Essentially, letting players choose how they want to play could go a long way for Blizzard.
Don't Be Greedy with Diablo 4
Blizzard was eventually able to mend Diablo 3, but they launched it with an auction house that was heavily and justifiably criticized by players. It was an unnecessary addition based on money-making that had a detrimental effect on the game itself, and Blizzard should be hesitant to do the same again. Instead, Diablo 4 should focus on what its players want. No gambling, no auctions, no loot boxes.
Diablo Immortal could include heavy emphasis on microtransactions if it follows the mobile game path (and it's what its developer NetEase is known for), and Diablo 4 should be the opposite. In effect, Diablo 4 should be kept honest, with an emphasis on the gameplay and bringing players back not through cheap tricks, but through enjoyable gameplay and an intense sense of replayability.
One would think that the existence of Diablo Immortal (and those other Blizzard mobile games) will allow Diablo 4 to have a more straightforward business model. After all, removing any predatory steps is more likely to build player trust, and long-term that kind of trust is what games need to bring in new fans after an honest gaming experience.
That bring us to the end of this rundown of potential changes to make Diablo 4 a force to be reckoned with. Although it may still be some time before the announcement, hopefully Diablo 4 will prove to be relatively close by, and leave players satisfied with what Blizzard has in store for them.