You can play Smash Karts in a99.io as unblocked.
What you need to do in Smash Karts is a game where you have to destroy the most opponents within 150 seconds when you enter the game. Destroy your other opponents by taking the Features on the ground. Everyone is alone in the game. You can steer your vehicle with "W, A, S, D" and "Arrow keys". It will be enough to hold down the "SPACE" key to shoot. You have to be # 1 to win the game.