I have a petite flat 2 beds and kitchen diner. Looking for ideas to decorate. Will be with 2 children under 8. Total space 55sq metres

Free space dimensions in centimetres:
Hallway 116 wide x 360 long
Kitchen 180 wide to window x 190 long
Lounge area 320 wide x340 long
Bed 1: 285 wide x 297 long
Bed 2 en-suite: 175 long x 285 wide
Cupboard in lounge diner is 48 wide x 77 long
Ceiling to floor height 230

Between the two Lounge diner windows is a door.
Tv point is on wall shared by hallway.
Under each window is a radiator.

I’d like to incorporate a feature wall if possible. Walls are all white and flooring is grey.
Clever storage will be needed