Global Game Jam
The Global Game Jam (GGJ) is the world's largest game jam event. Think of it as a hackathon focused on game development. It is the growth of an idea that in today’s heavily connected world, we could come together, be creative, share experiences and express ourselves in a multitude of ways using video games – it is very universal. The weekend stirs a global creative buzz in games… -- [About Global Game Jam]
Also, here is the official austrian page http://www.austriagamejam.org
The "main" location in vienna is at Neu Marx and will provide food stuffs for a modest 20e (which you will spend on ordering food anyway this weekend). Also interesting parties from game studios will come by to give some advice.
Metalab as an All-Nighter Location
If the site for the austrian global game jam in vienna isn't accessible 24/7, Metalab will accomodate all those with a little extra energy and motivation.
when is the next?
25.01.2013, check out http://www.austriagamejam.org for more info.