To win all fourteen stages without fighting, go to Niens (the NPC) in stage 1. Press F12 multiple times to lag the game. Run at the left side wall to pass through it. The NPC will automatically come to you. They will start to hit you, but cannot and will instead TK each other until they die. This will happen in every round.
Have another player keep running without hitting the door. Jump behind that player and press F12. Finally, jump again on the door and press F12 but do not come down on the player's head and do not stop running towards the door. If done correctly, you will not have to use glue or gloves anymore.