For only $5 this game is a steal!
Gunstars Heroes is a port of the Genesis game with a few added features. In addition to the original game you also get slightly enhanced graphics, online co-op, and trophies. The Trophies are disapointing. You can easily get 100% in under two hours, even if you've never played the game before. Why not have a trophy for beating it on hard? Why not have a trophy for beating it with a friend? Why not survive the mini game for a few minutes instead of just handing out trophies left and right?
But still, if you are a fan of Contra, Metal Slug, or maybe Little Big Planet you should check this out.