Um, this game is great. And it's only $2! To be fair, it's completely derivative of Mega Man, but it's one of those rare knock-offs that's arguably just as good. It's also kind of short, but again, only $2. The moving, jumping, and shooting feels really good and it's really precise. I'm also a fan of the graphical stylings and the music. And it looks way better in 3D.
Basically, if you own a 3DS, you need to get this game.