Nemesis is one of the coolest and most popular monsters in the Resident Evil games, but the Resident Evil: Apocalypse movie ruined the character. The first two Resident Evil games played host to their share of memorable adversaries, such as the infamous Tyrant, or the horrifically mutated boss form of William Birkin. It was Resident Evil 3 that introduced arguably the coolest of the bunch though in the Nemesis, a nearly invulnerable creature capable of appearing and wrecking shop at just about any possible time.
The Nemesis pursued Resident Evil 3 protagonist Jill Valentine endlessly and without delay, all the while saying the name of her Raccoon City police unit, STARS. As if the giant, hulking Nemesis wasn't imposing enough physically, the creature also came equipped with a rocket launcher, just to add even more danger to his surprise appearances. The Nemesis made it so players could never feel safe during Resident Evil 3, and that was a big reason why he became both loved and feared by fans.
Naturally, when Resident Evil started being made into movies, many fans looked forward not so patiently to Nemesis' big screen debut. As with many, many things in the Milla Jovovich-fronted movie series though, Nemesis wasn't translated to the film medium faithfully.
How Resident Evil: Apocalypse Ruined Nemesis
In the Resident Evil games, the Nemesis is stated to be the result of years of painstaking research by the Umbrella Corporation, and is the result of a Tyrant being infected by a creation called the Nemesis Alpha parasite. The Nemesis is purely a monster, and is never anything but a villain to be feared. While Resident Evil: Apocalypse keeps Nemesis' appearance mostly in line with his video game look, his overall characterization is changed for the worse, in a very big way.
Resident Evil: Apocalypse makes Nemesis not only a former human being, but one the viewer had already gotten to know in the original film, Matt Addison (Eric Mabius). Addison was abducted by Umbrella at the end of the movie, and was experimented on as part of the Nemesis Project, having become the creature by Apocalypse. Adding that backstory isn't necessarily a terrible thing, but the way it's used is, as Nemesis eventually remembers his human self, and assists Milla Jovovich's Alice in her fight against Umbrella. Making Nemesis a good guy was an absolutely terrible decision, and understandably elicited a collective groan from fans of the Resident Evil games. It's a big reason many game devotees gave up on the movies after Resident Evil: Apocalypse came out.