Pick your player! Any of the four can work! And with smooth and very smooth movement. Really. A & D to move, W to jump, and E to deal damage (player 1)! ⬅️ & ➡️ to move, ⬆️ to jump, and ⬇️ to deal damage (player 1)!
Some gravity. Thats all. And don’t play too much games in a row.