I kind of knew I would fail this challenge but wanted to start a new prototype and see where it would go.
My idea was a simple roguelike, as you play and level up a random island that you start on grows in size and spawns new items and resources.
I created a simple chunk manager which only held one chunk; am array of tiles. Each tile has a texture(s) and also a box2D collision box. I decided to use box2D to manage the collisions rather than roll my own.
Found a nice tileset http://opengameart.org/content/micro-tileset-overworld-and-dungeon on Open Game Art and started replacing water and grass tile placeholders; made a good start at using all of the tileset:
Made a start adding random items to the map (trees) and notifying the objects of collisions via box2D collision listeners:
Given I was only spending an hour or two each evening working on this I made some progress and made sure the code was clean and efficient, only actually managed 3/4 days out of the seven but am happy with what I got done and will work on this along side other prototypes.
I enjoyed starting a project from scratch and learning more about box2D collisions, there are some great tutorials available at http://www.iforce2d.net/b2dtut/collision-filtering, worth checking out. There is no harm in starting something you know you will fail from the start given you learn by doing so.