Summary: Anyone expecting anything close to the quality of Portal for fifteen bucks will be sorely disappointed. If approached as a distraction, disappointment may be mitigated to somewhere around "mild", and small pockets of enjoyment may occur.
Pros: Visually appealing, and leaderboards exist. The Slow dimension is indicative of how the game should have been. It's cheap.
Cons: Puzzles require a level of movement control that isn't suited to the first-person genre, which simply induces frustration. There's an awful lot of repetition, and very little humour.