It's like if they took the exploration parts of Metroid, made the main character a puddle of water, and made a game out of it.
This explains my general disinterest with downloadable or indie titles. Okay so you take a game mechanic from Metroid, which I love, and make the main character a... puddle? Why would I want to play as a puddle? It's just seems like too quirky of an idea. For me a big part of videogames is acting out a fantasy. Metroid gets it dead-on because being an intergalatic bounty hunter fighting space pirates is exactly the sort of thing I would fantasize about as a kid. But a puddle? No, I never in my life have thought "it would be so cool to be a puddle." And right there the appeal is gone. It's a creative idea but you can see the lack of marketability.
Of course if I can get it for free...
Ian, I believe that you unintentionally help to illustrate the brilliance of the game. I'll agree that marketing a game starring a puddle of water would be difficult (you seem to be living proof of that fact), but the amazing thing is that it works incredibly well within the design of the game. The developers have taken a relatively mundane thing and made controlling it, in my opinion, a hell of a lot of fun. With the main character a puddle of water, I can see why some might think it bland, but one could also say that the game is far more imaginative than any recent one released starring "X" soldier/stationary/space marine/etc. It makes me wonder what other boring, untapped objects might make for an entertaining game (if properly implemented, of course).