Porting of the fake 8-bit game Retro City Rampage to a real 8-bit system. Highly informative about a number of development challenges and associated solutions used in the NES days.

(Via: http://arstechnica.com/gaming/2013/02/retro-city-rampage-creator-makes-a-real-playable-nes-port/ )

Very cool. I've often heard PC programmers back in the day complain about how hard it was to get smooth scrolling (see John Carmack on Commander Keen 1). I didn't realise that the NES had dedicated scrolling hardware and that it's actually not possible to quickly update the graphics unless you are smooth scrolling!