At this point, you might have a lot of different inspiration sources. Now you have to pin down some design decisions.

EXERCISE

Gamestorming has collected a set of different methods which you can use to generate ideas in a creative process: https://gamestorming.com/. You can learn more about Gamestorming in this video:

Gamestorming (Vimeo)

Go to Gamestorming’s Games for Opening category or Game for Fresh Thinking category and choose one method which you think could be appropriate in a game jam setting. Remember, in this setting you will have limited time and resources, so pick a method you think will fit these constraints. These methods can get you started in the beginning of a game jam and help you making design decisions on your game idea. It can seem overwhelming with the amount of methods in this category, but just try out one. In the future, if you choose to try out more of these methods, you will get more experience on judging which method will fit to your unique design situation. https://gamestorming.com/category/games-for-opening/ 

Pick a method and try it out

• What went well with this method?
• What worked less well in this method?

Pick another method and try it out.
Compare the two methods.
Which one worked better? Why?