Very Boring.
The game offers more then just a regular Defense Game, as it has 'eight games in one,' but, that doesn't mean that it's fun. It gets really boring after the first day, due to the stall graphics (The blood could be drastically be improved), and the music selection was, well- kinda boring. It was pretty much only based in one genre, and they started to sound the same after a while. The selection of weapons was really small, and you threw in a Pellet Gun that did, like what, hardly any damage whatsoever?
The selection of enemies is another thing. It's out of the ordinary, with the Zombie Football players, Nazi Bowlers, etc. I mean, the idea of the enemies is original, but then it gets kinda stupid after a somewhat realization (or a short period of time). All in all, the game is better then some of the Defense games here, but it's nothing special.
Maybe if you improved the graphics, more 'plain' enemies, and more selection of weapons, and then a good array of music, it could be more fun to play?