Aquaria simply isn't getting that much attention because it's a small, indie PC release released digitally. Most of the big sites haven't even reviewed it. I doubt this has to do with ad-space or the like, because if you look at the recent IGN PC reviews, about 75% of the stuff they review is crap. Take Alvin and the Chipmunks or Swashbucklers for instance.
That being said, even if they did, I simply don't see how Aquaria would win many GOTY awards, even if it got its due. Don't get me wrong, Aquaria is an absolutely fantastic game, and certain better than most console games released this year, but stuff like BioShock, Mass Effect, Super Mario Galaxy, and The Orange Box are absolutely brutal competition.