BB Karate Kid

Each round you face a fresh challenger, and the bouts get tougher as you advance. Punches and kicks land one by one; the colour tells you who landed it. The final strike is always the KO — a finishing kick. When your karateka lands the KO, the opponent stays down and a new challenger steps up. Cash out after any win to collect your payout — it grows every round and always returns more than your stake. Beat all 10 challengers and you're Undisputed Champion.