Not all that bad.
Honestly, it's okay.
Pros:
-The contols were very, very smooth and precise, which was quite impressive. This is the most important aspect of a game like this, and it was done perfectly.
Cons:
-A lack of sound makes things rather dull. An Ambient piece would do wonders.
-Very glitchy. I seemed to clip or die my way through half the levels and finished the game in about 30-40 seconds.