How about a game which aims to produce an emotional reaction in the game by taking as a starting point an emotionless, boring and controlling society and then having the player inject 'colour' into the world, teach the other characters how to feel, and how to relate to each other. To teach them things like caring, compassion and sacrifice for a higher goal. This could be done literally, ie. a society run by computers and robots, where the player is the equivalent of 'Number Five' ie. the droid that came to life and had a soul. Or it could be done in the context of an ultra-competitive society that sees no use for emotions or empathy .. ie. the Ferengi meet the Vulcans. The player would seek to provoke a reaction, and 'infect' the other robots with his 'emotion engine'. This would be done by things like conversations, (think Planescape Torment), by hacking into the central computer, by teaching small robots life lessons etc. At the end the player would see a completely different society where the characters care for each other.

Sounds strongly reminiscent of the movie "Pleasantville" - two kids get sucked into the eponymous black and white 50s TV series and, with their modern sensibilities, introduce colour and depth to the inhabitants' lives.

I see four ways to do this: Labor, Puzzle, Infection and Battle

Labor: The "Q*Bert Method". The emotional influence you exert changes individual denizens of the world. If you want 100% conversion, you have to take your show on the road and convert every member of society. Some will be tougher than others, but you just have to keep your head down and plug away.

Puzzle: The "Dominoes Method". There's a hierarchy to the social mindset of the world. If you convert the head of a clan, the mayor of a town, or the president of a country, it "trickles down" and infuses all their subordinates in relatively short order. The higher up you go, the more efficient your efforts will be. Makes more sense with robots.

Infection: The "Zombie Method". Your emotional influence can be spread by those you've already turned. You convince one little kid and take a nap, and there will be four little kids on your side. Wait fifty years, and the whole world will be with you. Naturally, that would be a dumb game, so some kind of limits on time or extent of spread should be introduced.

Battle: The "McCarthyism Effect". Your influence will be recognized when it reaches a certain level, and a resistance will be mounted. This can be combined with any of the other sorts of transfer, and will lend a strategic element to the game.