What you don't get in replay value Antichamber makes up for with ample mind-boggling.
On several occasions I found myself picking my brain apart trying to solve what ended up being the most simple of puzzles.
I feel this was

a) because of my lack of intellect
or
b) Antichamber requires you to think outside the square, and throw away any conventional idea you have of how a puzzle works.

Either way, highly recommended FFO difficult puzzles.
Try to play it without a guide, I dare you.