The idea is really unique, I like the concept of having an alt world with a different blocks arrangement! Visually crisp, the UI is really polished. Well done!
Personally, I'd really like to see the idea get expanded into a puzzle game, or level designs with more focus on puzzles. I think it'll make for really interesting and mindbending gameplay.
I did also had 1 playthrough where I got stuck in the wall. I believe I opened a portal, and it closed while I was still inside the portal. The location I was standing on had a wall when no portal is around. I can't replicate it consistently afterwards though.
Great job overall! Would love to see more.