Really nice game! I liked the change of music as you jumped between the worlds and the art style was really nice in the upside down. I did play for quite a while and I would've liked if there was a point system or something in the game, just so you could compare yourself with earlier tries or maybe with your friends :D
Overall a very fun game, keep up the good work :)
I don't know if you've heard of Game Development World Championship before (gdwc2019) but it's a competition for indie game developers where they can submit their games and it's free! It's great if you want some more visibility for the game and it only takes a couple of minutes to join :)