Theme: Beneath the Surface
Interpreting "beneath the surface" as "secrets" and "hidden in plain sight" gave me the idea for a game about email. No, wait, bear with me.
This might actually be something. (Actually, no, it turned out to be quite awful.)
As an investigator with a shady branch that does not officially exist, you receive a hot tip from your best informant about something going down. Someone named Paul and someone named Sue are conspiring to dump their household garbage in the lake, to avoid paying for extra trash pickup! You don't know who they are or where they work, and you don't know when they're going to do it, but you had better figure it out before it happens or the city will undoubtedly be sued by the local environmental protection advocacy group. This is serious business. It's time to tap some corporate networks and intercept some email. The clock is ticking. Will you identify the conspirators and collect all the information you need in time to make your accusation stick and save the city budget?
The game will absolutely not be called "Where in the web is Carmen Sandiego?"
The game was originally planned to feature random level generation based on a pattern (which is to say, the formula for the level would be specified, but the characters cast for the roles, the time and date, and so on would be randomized; you might even call it a Calculated Formula if you have a certain background) with multiple locations that you could visit to observe these characters going about their ordinary suspicious business. It looked like it was workable on the whiteboard but simply failed to translate into an actual game. About 21 hours into the 48 hour compo period, I decided that spending more time working on it wasn't going to fix it, so I stopped working on it.
Here is the final version. It doesn't do much.