You you need an excuse to build something, a competition is a great motivator. The main Ludum Dare event can feel like a lot of pressure, so here is a simpler (or less pressured) version to get you started.
As next month the big fat Ludum Dare 29 happens, you're encouraged to use this jam as preparation and warm-up for the "real thing". This means: hone your skills, try out new tools, experiment with different gameplay ideas or even do things you normally don't do.
The theme for this miniLD is DEMAKES!
I chose this theme simply because it wasn't a theme for any Ludum Dare before. Officially demakes are remakes of already created games, by using less advanced technology, a more limited platform and/or a reduced scope. But as the purpose of Ludum Dare is to have fun, you may interpret this in any way you want. You should make something that is awesome to play, not that follows the theme slavishly.
Mini Ludum Dare 50 officially starts March 22nd and ends March 24th (in your timezone), but the submission form will be open for the rest of the month. Of course you may also start sooner. I recommend doing the game in 48 hours (or if you're a team, 72 hours) nonetheless, to keep the focus tight.
Rules: There are none, really. Teams are allowed, all tools are allowed, using preexisting content is allowed (but DO NOT infringe copyrights), all genres are allowed.
PS: For more cool game jams, visit the CompoHub!