The idea is solid and I think the optional stars to collect are a great addition. The visuals and audio are great as well. I think the triangle needs to be able to do more than just context-sensitive interactions, though, since it is very rarely used compared to the other shapes. I also got softlocked on the third level by accidentally sending the lift up as I was getting off it, which forced me to restart. That aside, great work on making this by yourself in 48 hours!