When you say prizes, you mean "cashprize" ? What happens if a non-US developer win the jam ?
Hi 0xNil - Yes, we mean the cash prize.
When the submission period is open, there will be a question that asks the developer for their country of residence. If the game is very polished and something we would be interested in having on the site, we will speak with the developer to offer a potential license that is not part of the contest.
We have worked with international developers before when licensing games for our site, as these are one time payments we make for licensing. The reason why this contest only allows US-residents to win is due to contest rules being different in each country which can cause complexity.