This new installment to the Resident Evil series comes with a unique twist. You contol both Rebecca Chambers, the S.T.A.R.S. Bravo team rookie, and Billy Coen, and escaped ex-marine convict. Some old characters return also; all of the Bravo team whose dead bodies were found in the mansion, and Wesker, who is working with Umbrella once again. There is also a new villian. (More will be known upon completion of the game.) He controls odd slug-like parasites who have the T-Virus in them, and they can form into people who attack you with stretchy arms. They seem hard, but you can use the Molotov Cocktails you make to kill them easily. He was also the man who first exposed the T-Virus to the mansion.
You get many weapons in the game, most in the first couple of hours. Handguns, Hunting Gun, Shotgun, Grenade Launcher, Molotov cocktail, and the ever-so-weak-ful survival knife. The zombies in this game are affected by the weapons in the usual way, and they don't need to be burned. Any type of insect monster you encounter will have an extremely powerful body, but a weak head.
The two characters in the game must be used to solve the puzzles. Some times you will be split up, but most of the time you are together. Some things that are new is that only Billy can move boxes, light fires, and has better defense. Rebecca has lower defense, can mix herbs and chemicals, and weighs less, but cannot operate some levers that Billy can. When you are moving around you control one character, but you switch quickly by pressing the X button. When your partner is following you, they shoot automatically, unless you switch it off in the info screen. Also, by pressing start, you can tell your partner to come/wait.
Another new feature is the fact that all the magic item chests are gone. You can now drop items, and use/combine them right when you pick them up, you will have to drop all your items in an easy access place so you can get them back. It is a little annoying, but a little more realistic.