I've yet to check out Proteus, but it looks both confusing and beautiful. The game releases for PlayStation Vita (and PS3) today in North America and tomorrow in Europe. It retails for $13.99 and there's also a 10% discount for PS+ subscribers for the next two weeks. Sony's offering the cross-buy promotion on this, so you get both versions for one price.
Like I said, I have no idea what Proteus is, but it appears to be an exploration game with a very unique art style. Below is a live action trailer featuring the developer talking about his inspiration for game. I hope to share my own experiences with the game soon.