That sounds like a great idea!
After we decided to give traumatizing cats a break, we're back to brainstorming game ideas. The title is the one-too-many-th idea that came out of our last brainstorming session. Though I do think with a heavy dose of faux-serious humour, it could be quite a good game.
Here's my favorite idea from our current session: You're a rage-infected human. You infect another person. And another. Soon, you're controlling a little band of zomb...no, rage-infected humans. You run through the city, enlarging your horde. Now there's two places this can go. Either this is a Katamari Damacy type game and the camera pans further and further out until you're controlling an enraged mass that overtakes cities, then countries, and then the entire world (and then aliens show up and you infect them too and then you go planet to planet infecting the entire galaxy (or maybe that's too much)).
Or, each level is set in a different era, and your goal is to amass enough infected to make it through the defenses surrounding a certain historical figure you would like to zombify. Imagine running through a revolutionary France inspired level (Zombie Marie Antoinette), a civil war era level (Zombie Lincoln), or an ancient Egypt level (Zombie King Tut... wait...) Who says that
zombie infestations rage infections always have to happen in the late 20th early 21st century?
Another idea - you have to fight off progressively more absurd procedurally generated apocalypses. Maybe tower defense style, maybe first person.
First it's rats. Then zombie rats. Then bears. Then zombie rat-bears. Then sharks. Then ninja sharks. Then zombie ninja shark-rats. And eventually unicycle riding zombie ninja bears with marshmallow guns. And so on.
And here's one that's been bothering me. I think it would be cool if there was a game such that for every three levels you played, you created a level, which was then used to populate other player's games with levels. The better you play through levels, the more points you earn to create more elaborate levels. The more you play, the more you get fed more elaborate levels. The concept is fine - but what kind of game fits into that concept? Maybe you have a bank of creatures. They have different costs and the amount of points you have is limited. Any creature you create starts at point A and you have to destroy something at point B. Between A and B there are obstacles that block and harm you. You must create the right types of creatures and guide them to circumvent/destroy these obstacles and eventually destroy point B. But this doesn't give any sort of compelling game to play when you have to create a level. Placing obstacles doesn't leave that much room for creativity. I need to think about this one more...