Well, if you have ever played Ace of Spades, it is quite similar. In my opinion, it's more of a complete version of Ace of Spades that just has cartoon-y characters and better graphics. I haven't played it yet so I don't have any opinions on how the gameplay is and everything.
Just a picture of what somebody built.
Someone shooting from a turret.
http://www.brick-force.com/http://www.youtube.com/watch?v=UTN2VHO9J98