If you ever make a sequel to this, how about adding RPG elements, treating each type of piece as a class with upgrades? It could be a cool tactical RPG, like FF: war of the lions, but simpler.
People keep saying only the trousers should be invisible, not his legs too. That would make him "the man with the see-through trousers" or "the man with no trousers". They cloak everything inside them, which means his legs.