Defeat other snakes and become the best!
Head to Head: To defeat other snakes this way, your snake has to be smaller than your opponents. Make sure your snake's head is in front of the opponent's head for the head-on collision & if you still don't get the defeat it could mean your snake is bigger than your opponents.
A great tactic you can try is to rely less on hitting other snakes with the head-on collision and try trapping them with your body.