I really missed a button to surrender, when I no longer have a way to win the match. In "sword and shield" challenge it was really frustrating to wait for shield to die, when I lost sword (which was many times). The same thing was when I started match by great mistake, then must to wait for my bots to run of health.
When I pressed other than left mouse button, the game gave me a message about "too young to use teleportation device". This is right, for it prevents people from cheating. But since then, when I press ANY mouse button, the game gives the same message. This way I cannot collect any particles!