A free weekend!
For the last number of Ludum Dares, I've always had something going on, making me have one less day to do stuff for the compo or jam. But not this weekend!
Now traditionally I've gone with using HaxeFlixel to make a game, but I think this time I'm going to go with my own C++ game engine. The main reason is that last time I had really inconsistent and unstable output to web builds, and outputting to Windows didn't work for some inane reason.
At least with my C++ game engine, audio will definitely work, shaders will work and I can output to Windows and Linux without any issues.
The obvious alternative is to use Unity, as it's the major supported game engine that I've had the next most experience with and another would be UE4, however, my issues with those are that I would be working around a GUI and a specific API instead of working on the game itself. MonoGame/FNA would be nice but it's been too long since I last worked on an XNA-like project, so that's likely to be a pass.
As for a theme, I've chosen to be rather specific with what I want, downvoting most themes. So far the only ones I've voted up are: Control two things at once, Safe in the dark and I have been here before. That being said regardless of what gets picked, I'm sure the majority of participants will immediately hate the results.