I also don't like claustrophobic conditions in games, despite having made a game all about squeezing through small areas! 😅 I think I erred a bit too much on the scale of the environment compared to the player, but I'd have to look at each section of each level to see where things could be improved.
I did try to put bright lights near to the first unmarked gap in the tutorial level but I couldn't get it to show up clearly and kind of gave up on that approach as a result. If I understood lighting in unity better I think it would have been a great approach.