I came across Aquaria while searching Google for "xxx superfish lady pr0n" (otherwise known as NeoGAF), and I was surprised to see what looked like a 2D indie PC game that doesn't suck. "Truly?", you cry, "Tell us more!"
A very beautiful game, Aquaria reminds me a lot of the last time I got my ass kicked by jellyfish and sharks in an undersea world, but according to the game's official Web site, it goes much farther than that. The UI is minimalistic (natch), with control boiling down to a single two-button mouse. The art style and graphic engine, on the other hand, are remarkably beautiful -- the game as a whole seems to be a fairly stellar reminder that 2D has some life left in it yet.
Aquaria is set to release on the PC in the coming Spring, but a game like this belongs on a console, particularly now that digital distribution is in full swing. Should Nintendo ever get around to presenting new content on the Wii's Virtual Console, I'd love to see Aquaria on the Wii -- let's face it, the next best thing to a mouse is a Wiimote, so they seem a perfect fit. Keep a look out for Aquaria in the Spring.