I tested the original experience in VR. Was it only just the one level?
One thing that didn't work very well was that the room scale was set up so that I had to move out of my physical location and tripped on items in the real world. It would have worked better to have both walls pushing into the player rather than forcing the player to keep stepping backward out of the space. I had issues tripping over things as I backed up to keep from being crushed by the wall.
I like the color locking when you placed the pieces, but wish there was other feedback to help me know audibly when I got the piece in the correct location.
The wall moved towards me at too fast of a pace. I didn't have time to look at the pieces and determine what actions I wanted to take before the wall had moved into my personal space. It would have worked better to have a starting room where the player could look around and physically move to the location that was most comfortable, then when they picked up the first piece the wall would move. In VR it's very common to need to start the program, put on the headset move into the proper position, and then be ready to play. By beginning the experience immediately, you didn't give the player time to get into the experience properly.
Like others have said before, more levels would be nice, especially if you slow the pace that the wall moves towards you. Realize in VR when someone's feeling claustrophobic they are likely to physically move the area that doesn't make them feel so compressed, even if that is outside of their chaperone boundaries. For an experience like this, the player should be gently crushed instead of pushed to one side of the room.
Picking up the objects felt natural, and putting them into the slots felt natural.
When you are polishing, adding sound can improve any VR experience. You can find free foley sounds that have wood creeks or metal machinery. This can enhance the player's feeling that they are in a physical space and reinforce the tension of the wall crushing in. Play around with different types of ambient music. You might find background music labeled for horror if you want the player to feel anxious, or look for things with water, wind, or woodwind instruments to make the play feel more at ease and be able to focus on the puzzle at hand. I recommend playing different songs while you play to the game so you can get a sense of what you'd like before adding the music directly into the experience. Also, make sure you layer sounds. Have a background sound, and something tied to the moving wall, AND random sounds from the environment like wind, murmurs, or shutting doors.
Thank you for sharing your experience, and I hope you make more VR experiences in the future.