The first game to ever feature on a PC, co-written by Bill Gates, was Donkey, a driving game in which you had to avoid donkeys. For years, it's been missing from your life, but don't worry: now you can get it on iOS.
Sometimes referred to as DONKEY.BAS — that was it's file name — it really shows off everything that is great and good about 8-bit games. It is ridiculously simple: you only use one button, to change lanes. It costs £0.69 in the app store, and it is worth every penny. [iTunes App Store]