Bit too spartan but does have some minimal framing and a light. I'd put drawers underneath instead of baskets. Do like the wooden, white walls. His room should be very light color since it has a sloping ceiling and is not very big.
Michael's Room cutting into the knee wall would offer more floor space, plus a very cozy sleeping nook. We would do just one bed, but it could be slightly enclosed, so there's a window at the head of the 'bed'.