Oni is a third-person action game, focused on melee combat mixed with some gunplay. The player can punch, kick, and throw enemies; progressing into later levels unlocks stronger moves and combos. There are ten different guns in Oni, including handguns, rifles, rocket launchers, and energy weapons. Power-ups such as "hyposprays", which heal damage, and cloaking devices, which render the player invisible, can be found scattered throughout the levels or on corpses. Since the player can carry only one weapon at a time and ammunition is scarce, hand-to-hand combat is the most effective and common means of defeating enemies.