Absolutely top notch stuff. Such a simple idea and it works so well! Love the music (reminds me of the VVVVVV soundtrack), the art style and the whole thing is dripping with pixel juice. Really great job!
Sidenote: I could totally see the same thing work in local big-screen 4-player co-operative multiplayer with game pad analog stick controls! Everyone moving and attacking in sync… that would be awesome.