This was such a well made experience, each section had some really cool ideas, and I love how one area can affect another area, really nice touch.
One thing I really liked is how you taught the player how to interact with the world without having to write it out. The first time I played and accidentally bumped into the rock and moved... That was a really nice touch, and you continued that to the other puzzles as well. I made sure to replay a second time so I could get the cassette as well, I really liked how you made that an optional task.
Really well done, and some really nice approaches to design, great work!