Especially the first time, it's easy to get lost in the enthusiasm of game jams. Here's some general advice to maximize your chances of finishing your game:
- Take breaks, sleep well. The biggest trap you could fall in is to spend as much time as humanly possible on your game. Except that sleep deprived people are just not as productive! Taking breaks regularly also helps keep an eye on the bigger picture.
- Make a small game, and make it playable as fast as possible. If you're aiming for a polished game, the ideal would be to have a playable version by Saturday night, leaving you Sunday to smooth things out, replace placeholders, add contents, and actually test the game.
- Cut scope when needed. Don't be afraid to cut features or even change the goal of your game as you realize things take longer than expected. Maintaining a todo-list is a good way to appreciate how much work you have left.
- Use techs you already know. This is not mandatory, because jams are also an opportunity to discover tech. But don't expect to be as productive if you're using, say, an engine or graphics software you've never tried before.
- Prepare your week-end. It is allowed to set up your project & tools before the jam starts. Making sure you have all your software & files ready can help you gain a few hours. Playing with the engine a little bit before the event can help you warm up as well.
- Have fun! Even if the week-end doesn't go as expected, you will certainly learn a lot during the week-end. And if you manage to finish a game, congratulations you did it! :D