Captain Acorn is a simple game. Defeat as many purple monsters as you can using Captain acorn's mighty acorn canon 2000 without having Captain Acorn be defeated.
However, if you touch the screen to fire an acorn, you also move our cute captain.
That makes things a little difficult if you just started playing this game. If you die, you start over on the same level. If you beat that level, you move on to the next one. The game does not save, so if you exit the game, and then open it again, you will be on the first level. There is no limit to the amount of levels.