Resident Evil Gaiden, known as Biohazard Gaiden in Japan, is an action-adventure game for the Game Boy Color co-developed by Capcom and M4, and first released on December 14, 2001. Received generally unfavorably by critics, the game marks a departure from other entries in the series, insofar as areas are explored with the playable character seen from a top-down perspective, with battles fought in first-person view. The story revolves around a viral outbreak on a passenger ship and has Leon S. Kennedy and Barry Burton return as protagonists.