Hey there! This is a very nice game and I did really enjoy the mechanic of switching between different objects.
The level design is really well done and I loved how the mechanic was used. I think this can def be made into a real game if you expand on this mechanic more and maybe even add some lore.
I did really like at the end also how you can see it gets a bit lighter which was just a small but nice detail and the surface pixel art was really nice.
One small critique, during some sections when you have to switch between the white monster thing continuously to head upwards, there were parts where my camera can't see the one above and I thought I was stuck for like a minute. Maybe if you could somehow make it easier to see that you need to go up by giving the camera more upwards bias that would be nice.
But yeah, overall I really liked this game, great entry!