I was blown away by this game after only 10 minutes of playing. I highly recommend it if you're into surreal atmospheric horror or a fan of Serial Experiments Lain or yume nikki.
There is also a story and an ending that can be reached. You'll probably figure out how to progress after playing for a few hours.
I made a guide here (warning: messy and probably somewhat inaccurate in certain parts) on how to explore the game if you need it. However, you really should go in blind, unless you find yourself unable to progress.