You don't need to develop an entire game under a week, just follow the task and you will be more than fine. Statistically AAA game released only for desktop has less chances to make it to the second round than underdeveloped game built for web. So what I am trying to say is that it is not about how much time you can invest in development, it's more about following the task, in the end it is not a "sprint" but a "marathon" type of jam.