The game runs pretty well and supports two players, so I'd recommend playing it with someone else.
The vs AI mode is pretty unfair, meaning you'll most likely get shot with pinpoint accuracy whenever your opponent fires at you, before you can even move the crosshair on it's fast and small frame. But then you'll realize you can shoot just above the ledges and easily kill him even without getting hit once. The music and sound effect match the whole theme of the game, so no complaints there.
The mode selection was tricky to figure out because you have to leave the green dot on for 1-2 seconds before it launches the match. A minor complaint, but it can be an issue to unpatient people :P