Not a bad concept; there wasn't much point to defending except for the sake of it though - maybe a scoring system based around time lasted would have helped with this? Also didn't expect that the body would be stunned by enemy bullets, given that the head seems to block everything with no negative effects (I thought the body movement was bugged for a while as a result - probably fixable by making it more evident what's happening when the body gets hit, i.e. with a visual or sound effect).