The game was good and had really good GameBoy feel, but I felt that it was very frustrating as well. I never made it past the second level, but there a segment that involved jumping up a bunch of falling platforms that is excruciatingly difficult to do without wasting your lives. After dying ten or so times and only making it past that part twice, I gave up.
I think the game would be better if the difficulty curve was smoothed a bit as it's kind of jarring how difficult it gets within two levels.
Sorry if this seems overly negative. Your game is really cool and has really nice music and GB feel!