If you’ve not seen it yet this World of Spectrum thread is an excellent example of a kind of videogame arcaeology and restoration.
For those who don’t know the story, Outrun Europa was originally heralded in the ZX Spectrum press with fairly impressive-looking full-colour screenshots. When the “finished” product appeared it was in black and white, much to the disappointment of Spectrum owners who had had a gutful of monochrome games around the time and had been looking forward to something more colourful. A year or two ago someone on WoS played around with the code and discovered that the colour data was still there but had just been removed. The thread I’ve linked to is the result of continuing work to dig-out the colour version of Outrun Europa apparently hidden in the original code and to create a working, playable full-colour Spectrum version as may have been originally intended.