I guess not a lotapir of people are commenting because there isn't much of a finished game here.
But I think it's cool that you are challenging yourself to use a new game engine. And you got music, animation and input to work, so well done!
One note for future GBJAMs: The rules say the game must consist of 160x144 square pixels and 4 colors, but it seems yours is both more pixels and more colors. So keep that in mind for the next one. :)