Heyo! much like other jams, you have 48 hours to create a piece of creative expression. In mehu jam specifically, you don't actually have to make a game! If you are a composer you could make a soundtrack - audioscape - foley etc of an imaginary game or a game that exists, or just music on its own.
Alternatively, you could find collaborators and make a game together with others!
The discord server has a channel for introducing yourself and teaming up. The opening ceremony / theme reveal will be held there, so you definitely should join if you haven't already.
There is also a channel listing resources / suggestions for newcomers with links to beginner-friendly / no-code / low-code game engines, music making tools etc...
