Not just playable games, but also games that are different from the usual stuff you see. Was there any hacking type games like Uplink before Introversion released it?
The weeping woman, the cough. Damn I am so tempted to play it again (does it make me a heartless psycho?), but I am at work :(
This is a great example of how some well though out details can play a massive role. Would the game be the same without the soundtrack, with the sounds of crying and coughing? It still would be a good game but not THAT good.
Darwinia was a shooter/strategy game set inside virtual world.
Even Defcon is unconventional. A game about nuclear war and mutual assured destruction with a retro asthetic.