Here, folks, is gaming on the original handheld - a calculator. While you're still snickering over spelling out BOOBLESS and HELL upside down on yours, some guy's gone and run Doom - real Doom - on a Texas Instruments Nspire.
The admin of the TI calculator enthusiast site (i.e. - gang o' nerds) Omnimaga got the game running for about 30 seconds before it crashed the calculator. Not bad, since the device has, roughly, the memory and processing power of a mid-1990s desktop.