In regards to what csanyk said about campagining themes, I will avoid putting up most of my own votes.

Afterlife – This theme makes me think of things like various heavens and hells.

Chaos – This would be fun to program, there are so many ways this theme could be interpretted.

Claustrophobia – This would be hard I suppose to program into a game, however any challenge is welcome!

Growth – I think of plants and self replicating robots for this theme wierdly… This was also used in LD #7

Infection – This is a bit like quarantine but slightly broader so more ideas can come out of it. This was also used in LD #4

Inside – This reminds me of the Alone, Escape and Tiny world themes.

Parallel Worlds – Inter dimensional travel between parallel worlds? I’m there!

Science – Very broad, but may encourage people to make their games more scientific?

Shadows – I really would like this one to get through, there are so many things you can do with shadows!

Stranded – I think of an abandoned island or factory with this theme.

Surveillance – I can’t think of anything good for this theme yet, maybe a spy type game?

Time Loop – This may sound like a mechanic but it could also be easily used in a storyline. This one will definitely be hard and fun to program!