Stanford Alumni is hosting The Cardinal Game Jam in Silicon Valley. This one has a shortened time constraint of 26 hours compared to a traditional 48 hour jam. Thanks to Weeby.co, I'll be heading there to participate, all expenses paid with the reasonable condition that I use their platform technology along with something compatible like Unity or Cocos2D-x.
Unity is a rock solid engine for multiple purposes. It is very suitable for time constrained game jams because getting up and running is just so easy. Creating new object types for a project is just a matter of attaching components, including script files written in a high level language like C#. This excellent multipage tutorial demonstrates the basics.
Perhaps it will be my engine of choice in the future.