The recently released XBLA side-scroller Insanely Twisted Shadow Planet wears each of its various influences proudly on its sleeve. You'll probably see them if you play it, but if I had to list them all, I'd take a deep breath and say: A moderately tripped-out short from Fantasia grafted onto PixelJunk Shooter through the lens of Limbo by way of Shadow Complex, all wrapped up in a weirdo Dr. Seuss-gone-wrong art-style.
But of course, when I say that it channels Shadow Complex, I mean that it actually channels Metroid and Castlevania, because Insanely Twisted Shadow Planet is a "Metroidvainia" game, through and through. (I believe the fact that we still grudgingly surround the word "Metroidvainia" in quotation marks means that the term itself is never going to be more than an inelegant portmanteau. But what term to use in its place? I have no answer.)
Players spend much of ITSP flitting about in a little spacecraft that calls to mind nothing so much as Marvin the Martian's wee little flying saucer, using various upgrades to open different sections of a vast, backtrackable map. The game's defining aspect is certainly Michel Gagné's fantastic artwork, all silhouetted beasties and tentacles and ice-sculptures and deadly plant-life, lunging and swaying about the titular planet's surface. (For reference, check out the video that Totilo shot last week.)