Took me some time to realise that collisions with (a) the rocks you're trying to mine and (b) the bottom of the tractor beam (?) are fatal and I'm supposed to avoid that. Once I'd got it, there is potential here; it's Thrust, but with the added attraction that the rock follows you around and you mustn't collide with it. Obviously it's just a prototype and therefore doesn't have music or backstory or anything, but I think this could be quite entertaining once it becomes a game!