First of all - mad respect for making a GAME BOY game. Absolute madman.
Controls are alright, it's a decent plaformer. The menu for skill (probably?) choice doesn't seem to do anything, and the witch's sprite clips into it if you stand on the right side of the screen.
The intro sequence is a bit too long for my liking, BUT the lava section is actually pretty good, with new enemies and boulders rolling. I managed to jump over the first one so I didn't get the "chase", and the second one killed me. But that part was pretty fun!
Enemy/Witch sprites seem a bit at odds with the background sprites, maybe because the coloring is less striking. But they are distinguishable, and that's what matters I guess.
I would prefer to have a bit more checkpoints. Lamps look like checkpoints, but either I'm too dumb to activate them, or they are just part of the scenery.
Keep it up!