JUICE: Nicely polished, especially jumping. The controls were smooth, and the particles and sound made it feel satisfying.
Gameplay: This is the main area I have problems with. Jumping over spikes is not my favourite mechanic, and the combination of slippery movement and spikes that kill you from the side is really frustrating. Maybe check the collision normal when hitting a spike?
Graphics: Good sprite work, nice use of chromatic aberration. The floaty background particles are a nice touch.
Sound Design: The music is an interesting mix of chirpy and eerie. I think it fits well.
Respect of the Themes: I like the concept. As I understand it, for each level, you have to reach the portal, then traverse the level in reverse in the mirror dimension. However, since the levers and buttons change the level layout so much, the auther version often didn't feel like a mirror image. It might have been better to have fewer mechanics, and focus more on that core concept, which is actually really cool.
Overall, a good game. Well done!