So I don't want to tell anyone what to do, I just want to share my opinion and personal taste towards LD themes.

I love themes that are as ambiguous as possible and as broad as possible. Themes like "darkness", "sustainability" or "Out of scale" are really good. These can be used in so many ways in either gameplay, visuals or story. For example, "darkness" can play with literal darkness, where you play in some gloomy environment, or you can use it for a horror story. Or it can be a game mechanic where darkness is used to kill enemies with, or be killed by it. Or it can go even deeper like having darkness in your heart or soul, writing a story about depression or sadness.

No matter what theme, I know we will all have a great time next weekend!