It is difficult to make a 3D puzzle platformer but you have done it exceedingly well! Congratulations! I am enamored by the visual style and the universe switching mechanic. The fact that you can take items you pick up from each dimension blew my mind lol. 

The following are some notes I took while playing the game:

• The switching between dimensions mechanic is very quick and seamless. I also love the sound effect. Its pretty awesome that you can take boxes with you. I found that after switching the boxes would sometimes start spinning. You may be able to fix that issue by manually setting its rotational velocity to zero.
• I like how you can stand on the cubes. It makes it easier to to place items in hard to reach places. 
• The first turret I encountered was not very threatening. It would aim towards me but shoot the floor in front of it. Idk if that was a bug or not.
• In the middle of playing the game i had to exit the screen but when I came back and tried to resume I could no longer control the character. The game was not frozen either since particle effects were still playing but using the mouse and keyboard did nothing.
• I am loving the 3D art style. It makes me feel like I am in a lab experiment like the portal games. I also like the inclusion of items like cars and medieval knights. It makes me feel like I am traveling through time. 
• I think that the platforming combined with the universe switching could be a fully fledged game by itself. You have a great concept on your hands.
• I appreciate you including the pink ghost platforms to help but I feel that it takes away from the challenge and also the charm since the game is all about discovery as the player switches between universes.
• I think the game experience could be improved by some background music. There are a lot of websites out there that offer royalty free music. I have a spreadsheet that could help https://gamedevelopmentwiki.readthedocs.io/en/latest/community/assets.html
• In the last level with the 3 buttons, the buttons are close enough so that 1 box can rest on 2 buttons lol.

Overall Well Done!

Overall Enjoyment: The puzzles were quite easy but that is fine for a game jam, I especially loved some of the platforming levels, the bounce pads  felt very fun to use.

Use of Theme:  It wasn't a very creative use of the theme but it definitely worked for your game and made some interesting puzzles.

Gameplay Enjoyment: Considering that it was a main mechanic It didn't feel that the universe switching ability was involved enough, that being said, I loved the puzzle where you figured out that you could bring the blocks with you when you switched dimension.

Audio: Could really benefit from a sound track, but the absence of one didn't affect the game too much.

Visuals: Amazing that you managed to create a 3D game with good models in such a short time frame, Well Done!

Creativity: Gave me massive portal vibes, and I loved it, thought the mechanic was very interesting.

Really well done, I enjoyed the puzzles a lot, congrats on submitting :).

Overall Enjoyment: The puzzles were quite easy but that is fine for a game jam, I especially loved some of the platforming levels, the bounce pads  felt very fun to use.

Use of Theme:  It wasn't a very creative use of the theme but it definitely worked for your game and made some interesting puzzles.

Gameplay Enjoyment: Considering that it was a main mechanic It didn't feel that the universe switching ability was involved enough, that being said, I loved the puzzle where you figured out that you could bring the blocks with you when you switched dimension.

Audio: Could really benefit from a sound track, but the absence of one didn't affect the game too much.

Visuals: Amazing that you managed to create a 3D game with good models in such a short time frame, Well Done!

Creativity: Gave me massive portal vibes, and I loved it, thought the mechanic was very interesting.

Really well done, I enjoyed the puzzles a lot, congrats on submitting :).

Its like portal! I love portal.

Game was great, and was 3D so that made it stand out in these submissions! My only problem was that it was rather laggy, most likely because it was a Web GL instead of a download. The lag made it difficult to pass the jumping section, but I can tell without lag that would have been my favorite part. 

Very cool game, great job!