Oh, damn it, that was mad! Up until the 7th minute, I was playing by the rules and thought it was a new Tetris, but then I just started spam-clicking around my main tower, and it turned into a kind of clicker game (I lasted about 9 minutes and 20 seconds). Maybe if you forbid double-clicking (at least before the 9th minute), it would make the game less cheating? x))
Good game after all!