I enjoyed it, it's simple to pick up and play and the art style is nice. I'm pretty sure I made it through every level without dying, and there was a nice escalation with each one. The intro cutscene is cool, with the flythrough of the steps and the logos.
Out of curiosity how did you implement the shadow/light detection? I'm using a light-based visibility system in my game so it's always neat to see other people's takes on it.
Oh and I noticed that mouselook isn't stopped when opening the option menu, so I would suggest implementing that just as a QOL feature.
I hope the person who got this for secret Santa enjoyed it!