Same problem as Dener had, I guess that's just an unmentioned limit on moves you can make? I liked the concept though, and I'd also suggest using transitions instead of straight .x/.y assignments for the blocks' movement to feel smooth. Good job!
yes will use transition in futurebut currently code depends on x and y gridmanager keeps track of cubes, and cubes also keep track of their space in the grid based on x and y
