Small Arms is one of the greatest games that Xbox live Arcade currently has to offer.
First off, the graphics and sound are really amazing for an arcade game. The explosions almost rival current gen games and the character models outdo the models on Kameo. The sound is also pretty much perfect with the sound effects and the background music being really matched for this game.
The gameplay is quite similar to SSB. It's a 2d brawling game that puts a little to much emphasis in getting the best weapons. However, every other aspect of the gameplay is executed pretty good.
The best part of this game though is by far in the multiplayer. a 4 player free for all with the option of having several different maps. The online in this game is just plain fun. There's no better way to describe it.
If you're like me and really liked games like SSB and wished you could play it online then you really have to get this game.