Hello, this is my submission.
First of all-I separated entrance from the rest of the house, because of different air temperature inside and outside. In the entrance hall you may have some shelf and storage (for shoes, jackets etc.).
When you get in the house-almost everything is positioned on the right side, so you can have clean path. There is kitchenette with dining table and big sofa for enjoying with your family, watching TV and having some quality family time. Parental bedroom is separated with the staircase, so you can have some peace when you need it. Mezzanine is kids bedroom. It looks like there are 2 rooms, so kids can have their own space for sleeping, reading, playing, but yet-there is enough space for them to play around together.
I hope you like this concept.
P.s. It wasn't possible to add more then 1 3d image, so I added it with floor plan.