House
Main Room
The astro CD player, green bear, stained glass window, sleek clock, and QR painting seem out of place.
Left Room
I'm not really a fan of picture rooms. But if that's what you want to make it, that's fine.
Right Room
The cubby with the GameCube stands out like a sore thumb as do the astro chair, lantern, and phonograph. The cat, not really something I'd have in a room with regal items, but if you want to have a classy cat, that's cool. I think other pastel shades would do great in this room.
2nd Room
From what I'm getting at, this is a kitchen. I'd do away with the lemon looking tables behind the display glass and put maybe a tea table or neutral table there to hold both items. The display glass should be facing the opposite direction. I'd exchange the lamps and stereo with something a bit more fitting.
Basement
Music room? I'd throw down a music-room wall and floor from Saharah and arrange each instrument to give the impression that some people are about to start a band of some sort. The wall and floor are hard to come by, so you not having them is understandable.