The art and the character are really cute! I also really like the kit (jump with a flutter, and a boomerang you can aim). I also like that the boomerang can pick up coins for you.
I don't play retro games too often, but the collision is a little sketchy, which makes platforming a bit clunky for me personally. There also weren't any enemies to use the boomerang on, so was it just for collecting coins? The game would probably benefit from a more structured goal/more involved game play.
Overall solid entry though!