Congratulations on your first game, that is a fantastic accomplishment! Well done! I beat the first 25 levels then stopped. It was pretty fun. Since you asked for feedback, probably the two biggest things I noticed were:

I really liked the game! Congratulations on your first! :D. I liked how the cube moving slow but was at a perfect speed balance with the rest of the game. There’s a little collision detection on the side of the spikes but its not major.

It’s pretty tough at parts but really fun to! The idea is simple enough, but still engaging to keep me playing