Mr Stump's Dentures has a longer history than its simple premise suggests.
Origins
The game began in December 2002, the work of a small UK team led under the Euphoric Rush banner. It shipped as a standalone mrstumps.exe with 79 levels, the original game copyright dated 2004.
The premise
The story is pure dream-logic: Mr Stump went to bed after a few too many at the pub, and dreamt himself into a hostile platformer. His dentures have been stolen, and the whole game is his stumbling quest to get them back before he can wake up.
Today
The game is now preserved and maintained as an open project; the source lives on GitHub at tibberous/mr-stumps-dentures, and this site is its official home. It is operated by AcquisitionInvest LLC.