I quite enjoyed this. Picked it up off their site during that sale. Atmosphere is really good, and I enjoyed the filter mechanic and the other little changes that made it less run-of-the-mill.
Definitely worth picking up on sale, and maybe worth paying full if you have the money. I don't buy many games at full price these days. Guess I'm getting cheap. That, or I buy way too many games to buy them all at full price. Take your pick. =)