This game has a really special presentation, it's got fantastic pixel art, moody and atmospheric yet surprisingly mostly accurate-sounding music, the sound effects are certainly pretty accurate, and there's not much here that wouldn't really be possible on a real Game Boy, as far as I was able to go you're sticking to only 1 BG layer and even the 3-colours-per-sprite limitation, all of which is very commendable!
All that said, I'm sorry I couldn't really get too into this game, the camera was a bit nausea-inducing, it pans to the direction you press a little too fast, and that makes everything harder to see, which leads to a lot of frustrating deaths...
You have a lot of talent though, keep it up!