Back when I first played this it took hold of my brain so tightly. On it's own it was a very solid puzzle platformer with great music and atmosphere, but the way it continued to open up and deepen in complexity was very captivating to me. It had an air of mystery around it that I still haven't totally seen replicated. I wish I still had my page of handwritten notes that I made when solving some of the more difficult late game puzzles.

There's something to be said about the actual puzzle content of the game, which is fun but lacks an amount of depth. For the most part I would consider the true appeal here to be the act of uncovering the game's hidden mechanics and searching for secrets, rather than pure puzzle solving. The late game secrets and puzzles range from simple once you know the trick, to horribly obtuse. This doesn't necessarily win it any points as a puzzle game, but it does serve to deepen the mystery of the game, which works in it's favor in the end. The notorious Monolith "puzzle" remaining unsolved would be easy to dismiss as bad design, but at the time it I played the game it only served to deepen the game's atmosphere and my investment in it. Overall, considering it's one of the main things that gets brought up in discussion around the game only shows how memorable it is.

Overall if you want a pure puzzle game there are better options. If you want a fun platformer with a lot of atmosphere and character, this still fills that niche very well. I have a very strong fondness for it and probably always will, and the experience of playing it makes up for any shortcomings it has.