Resident Evil Zero is a third-person survival horror video game and a prequel to the first Resident Evil. The gameplay remains largely the same as previous entries in the series but also introduces what it calls a partner zapping system, which allows you to switch between the two characters Rebecca and Billy at any time. This feature must be used at times, as the game requires both characters to work together to solve some puzzles. New to the game are a bunch of terrifying enemies, like the mutant centipede, new areas to explore, and the ability to drop items on the ground instead of having to find an item box.