This is a very cool concept. I love the dimension switching, I'm a big fan of that. The pixel art and the music is really good as well.
The level design is well done, I really appreciate the scale in difficulty and teaching the players the mechanics so it's more satisfying when we solve the puzzle. I would love to see this idea expanded upon in the future!
One small bug, when in full screen for some reason the next level button wouldn't work, but that's only in full screen, outside of that it works.
Overall I really like this game and its a great game jam entry :D