Unnamed Fiasco is a competitive local multiplayer game. Players control distinct characters, such as an old lady with a moustache or a lucha-libre baby fighter, in matches against up to three friends. The game's core mechanic involves fallen characters creating clones that repeat their past actions, providing assistance to the surviving player. Gameplay is further diversified by "Minute Madness" modifiers that randomly alter match conditions, and power-ups collected from piñatas. Players can compete across 24 maps spanning themes like Mayan temples and bullrings, utilizing modes including Deathmatch, Capture the Flag, and Treasure Hunt.
Beyond its local multiplayer, Unnamed Fiasco presents over 40 single-player challenges that blend action, puzzles, and skill-based gameplay, supported by online leaderboards. The game's unique clone system encourages strategic thinking, as players must anticipate their movements to leverage past actions effectively. Environmental hazards, such as laboratory lasers, and a variety of power-ups add further layers to the chaotic, fast-paced matches.