Efficiently designed. I like how the bathroom opens to the bedroom and the den (which could be a decent guest room with an addition of a murphy bed or sleeper sofa.
I would floor the entire unit (except the bathroom) with hardwood or laminate to create a nice flow through out and make the space seem larger. It also eliminates the slightly odd transition between the kitchen tile to the living room and den (the corner of the tile floor ends short of the wall).
I would have the closet/linen open into the den than into the kitchen/dining area. That would free up some wall space in the main living area and it would look less cluttered, and the closet could be used as a guest bedroom closet if you wish.
The bedroom door happens to be in the middle of the living room wall -- having the living room furniture facing the bedroom door is not really ideal especially when you have company. If you are a big couch potato, finding a wall for the TV could be challenging in this small space.