Oh what a glorious glitch
If you keep holding down C when you cross the finish line, your gun keeps shooting on it's own for the rest of the game. Except when you press C on the next level, additional bullets get sent out. Don't fix it, because I like having a machine gun by level 3 ;)
As for everything else, the mario rock music was ftw, the shooting of everyone was ftw, and the hilarity of mario with a shotgun was ftw. I didn't figure out how to aim my gun like in the last game, but when you have a machine gun, who cares? Graphics wise, well, they were sprites. But they were animated well enough so that I wouldn't care.
Ultimate violence ftw!