multiplayer, Dead Island, cooperative gameplay, online, up to 4 players, open world, zombie survival, first-person, action RPG, team strategy, voice chat, shared missions, tropical island resort, dynamic day-night cycle, melee combat, crafting weapons, skill trees, character customization, drop-in drop-out, PvE, in-game communication, realistic graphics, immersive sound effects, HDR lighting, detailed environment textures.