We’re done!
This was a surprisingly stressless weekend. It’s so much easier if you work in a group 
Ok, and we didn’t reach for the skies. We worked with melonJS, which sets the type of the game almost naturally to Jump’n’Run (at least if you follow the tutorial). But after all the game works pretty nice and we had much fun and that’s all what matters 
Hope you guys had comparable experiences 
Have a look at Jump’o’lution if you like:
http://www.ludumdare.com/compo/ludum-dare-24/?action=preview&uid=16049
