Not a bad game, however it seem's a little unfinished. It is missing features such as power-ups, the ability to pause the game, how far you are to the next wave, the ability to buy guns between waves, the score for both players, to compare for bragging rights as such.
However I do like the concept of it, the music isn't bad, it compliments the artwork with the whole retro-esqe sort of style which I dig, the guns you are given are fun and all in all it's not a bad game.