What do Costume Quest, Iron Brigade and Stacking all have in common? They all started as part of Amnesia Fortnight.

Double Fine is making their annual game jam, known as Amnesia Fortnight, public this year, allowing people to view and vote for four game ideas that will be made into prototypes (if they are willing to donate at least $1 through the Humble Bundle).

Just as with any Humble Bundle purchase, you can pay what you want and decide how much of your donation goes to charity.

Check out the video explaining the program and briefly detailing all 23 of the prototypes below.

The process of making these prototypes will be live streamed and documented by 2PlayerProductions, the same makers of the Double Fine Aventure making-of documentary.

Voters will get a chance to try out the four prototypes chosen in the process and pick their favorites as well as a chance to play the older prototypes that would go on to be Once Upon a Monster and Costume Quest.

Prototypes range from a puzzle-brawler featuring characters from past Double Fine games to a 2D platformer in which you play the villain and construct the levels.

Head on over to the official site to donate and vote on which prototype you want to see made.