Okay so I have now put a total of 60 minutes into coding this game, and about a half hour looking for some art. I have a working prototype of the platformer engine. I am using a object layer in tiled to create the collision map, and tile layers to create the displayed map. Looks pretty so far. Just put it on github http://github.com/sugarware/gravity. Rethinking using 6.67408 as the name. Hopefully I will find time to actually make this game.