This is GameCube's 2nd RE game after the remake of the original Resident Evil and it isn't a sequel. It's much more than a prequel and I'll explain why is it. When the original Resident Evil infected the Psone back in 1996, players wondered how the zombie outbreak all began in the first place when the story unfolded. Capcom remade the original game for the GameCube as part of the exclusive deal with capcom and players were still left wondering how it all happened in the first place, until capcom got the idea to go back in time with the series and that's when Resident Evil Zero was born. The game goes back in time to where it all started and that lead to the zombie outbreak to happen in the original game.
Resident Evil Zero was originally going to be released on the Nintendo 64. It's true, but that was when the console was almost at the end of it's life, so capcom moved the game to gamecube as part of the exclusive deal with capcom.
The game introduces the Bravo Team, but it was the original game that first introduced the team along with the S.T.A.R.S. team. The team are made up of Edward, Forrest, Joseph, Brad, Enrico, Richard and Rebecca - as you may remember from the original game. The game also introduces a brand new character called Billy Coen, who is a former U.S. Marine. You'll follow the team of how they ended up there and how they died, but mainly you will be in the shoes of Rebecca and Billy throughout the entire game. Albert Wesker returns and you'll find out that he's the brains behind all of this mess to begin with and William Birkin is also in this game from RE2.
The game has some new features, enemies and weapons, but it does lose a feature that everyone liked throughout the series. The notable and the biggest feature about this is that you can control two characters at once instead of one throughout the game and that's called Partner Zapping. The way this works is that you can swap between rebecca and billy at anytime or whatever room they're in if they are seperated. I bet many people disliked this feature, but makes it easier to kill zombies and monsters knowing that you have another pair of hands to help you. You can switch items between them and that's where the storage box comes in. There isn't one, so players will have to drop items on the floor, which is ridiculous.
After this game was originally announced for the nintendo 64 and was released for the gamecube. The game has came to the Wii with no new features or graphically enhancements like the RE Remake, but it does offer Wiimote controls now, which is not very good at all.
Despite the new features and lost features that many didn't like, this is still a very good game in the series.