If you've got an Android phone that's at least as powerful as the Nexus One/HTC Desire, and if you're reading this, odds are excellent that you do, you owe it to yourself to check out Wind-Up Knight. It's a classic sidescrolling platformer with up-to-date 3G graphics and a sense of humor to boot. It's a free download in the Android Market.
You are a pint-sized paladin, sent to rescue the king's daughter who has been kidnapped. Kidnap victim seems to be the primary occupation of princesses in video games, doesn't it? The kind is quite anxious to get his daughter back - he warns you in his parchment email ("FWD: OMG PR1NC355 GET!") that it will be on your quarterly review. An ad at the bottom that you can "get your own free hosting at GeoCastles" had me chuckling even before the first level started.
Check out some footage of an early version below:
Gameplay is a lot like the popular Wii and PC downloadable title Bit Trip Runner, in that your clockwork character runs without any direction. The player jumps or slashes via on-screen buttons, avoiding falls and spikes while constantly running through monsters. Graphics are impressive, even if the 2D gameplay is pretty simple - a perfect game for showing off your tablet to family members who might not appreciate more advanced controls. The first chapter of the game can be downloaded for free, with additional chapters available for a reasonable $1.99.