Battle Wheels

Two armored cars in a walled arena, and the loser is the one who stops moving. Damage comes from speed and angle, so ramming someone head-on is the worst available idea and catching them mid-turn is the best. Winning three rounds takes a league, and the garage between leagues sells faster cars and tougher wheels with the coins you earned. The upgrade path is shallow enough that a second player who has never opened the garage can still win, which is the only thing that matters here.