I find it hard to comment on this game. I'm generally not a big fan of platformers if the movement doesn't "fit" for me. So I didn't get very far in this game. I'm gonna dump my thoughts but they might mean nothing to you as I'm definitely not the target audience for this game :D but I'm doing it anyway because it looks like a lot of thought and effort was put into this game and you stated you want to develop it further.
I think the game is too pixelated, it's pretty hard to see what is going on with all the moving pixels on every screen. Is it just flavorful grass or flowers in the wind? Does it actually serve a gameplay purpose? Can I stand on this twig? It's hard to tell and there's not much feedback if it is a gameplay mechanic. Speaking of feedback, it's hard to tell what is dangerous and why it is. I didn't even see the spikes at first and wondered what happened, with a hard reset to the beginning of the screen, and then a hard reset to a few screens back. Audio cues would help a lot, I think.
But even after learning all these things, and learning how the game mechanics work, I couldn't get very far. The enemies respawn which makes it annoying when you die a bit later before you reach a new checkpoint, and the precision platforming in the rooms to the right was quite tedious for me so I didn't make it through that area. I don't feel like spending a lot of time mastering the enemy patterns and platforming mechanics of this game because I don't enjoy these kinds of games. Which is my fault, not yours! But it does mean I dropped it before reaching the good stuff.
I did like the intro cartoon storytelling, I thought that was done very well and it was a perfect start for the game.
All in all, it's probably a great game but it's not for me so I can't tell and you should probably ignore everything I said :D