Nice game and nice puzzles.
You can improve:
- A initial menu to the game
- Some background music for the atmosphere.
- Some tutorial.. I find out about the letter E only on the itch page.
- On level 2 I was able to exit from the field and go out.. you didn't put any collision. (here is a picture of me going down and your level on the top).
I am not expert in 3D games and how the games are complex to make, but I think is a really good start.
Good Job.