Meh. It's alright. Just a few problems.
Yeah, the concept of being invisible and the little orbs is good, but the jumping is unresponsive (I was hopping, yes, hopping, into a wall for a good 5 or 6 seconds before he decided to jump up, and which point I had to drop down again so that I could be visible and jump up to the next ledge, then the process repeated itself ad infinitum).
Still, not bad, just not especially good either.