It's a good game but it is way too easy. I beat it after upgrading the second cannon to level 3 and having the tornado weapon, no more than 10-15 minutes game time.
My favourite part was where you put annoying buttons on the screen, i.e walkthrough so when people are trying to play the game they click them instead.
I can't offer an honest opinion of the game without being downvoted? Bit stupid really.
I better just lie and say that it's the best game that's ever been created.