Sk8er says this "is an exact replica of my room in real life, be sure to check for fake walls which will help you navigate this monstrous room." - and it certainly does look like a proper bedroom, although it seems rather tidier than mine is. Not even any dust or fluff under the bed!
There are tunnels in the walls; luckily, you can just about see the secret panels that let you in, as the grey paint is just slightly lighter, up to a sharp edge. So, elevators and ramps take you to most of the high-level places where weapons and other pick-ups are to be found.
It is all very cleverly done, using just the conventional NAB textures I assume. AndSk8er seems to have just left his room for a minute - the computer is still on, apparently for playing the Luna Bonus
arena, though for some reason the colours seem a bit different from usual there.
So, not the first little-player map, or indeed the first bedroom, but very well put together. But if I was Sk8er, I think every time I went to bed I would be checking to see if a tiny whomper was floating just above the blankets...