Our first week of prototyping is complete, and we've made fair progress. Below is a screenshot of what we have so far. We've decided to use the Farseer Physics engine, based on Box2d. This allows a lot of flexibility, and eases our rapid prototyping. Below you can see a magnet that the robot is "locked" onto. There is a graphic overlayed to show which magnet the robot is focused on. The 360's controller has two triggers which control the amount of push or pull towards the magnet. This is already turning into a lot of fun!
More updates to come soon!