A bit of shelving to anchor the space, wall art, a couple of smallish chairs and a small rug to make it livable. "Play areas" often look more like storage areas.

Would you recommend centering things on the wall or using the edge of the couch as the “end” and then having a section above the small portion of the couch?

Hi. What’s to the left of window wall? Any usable space there? I’d def use the back of the sofa for a low but wide storage cabinet. Easel looks good where it is. You could put another low cabinet to the right of it to maximize more storage. Cute rug but not necessary and a table with chairs under window. Keep floor space for play.

As far as wall decor best to keep it neutral and not for a child. Maybe some type of wall hanging. Boho look with chunky yarn and tassels maybe.

Next to the sofa, if there’s room, I’d put a small accent table for people to use for a glass, etc. since I see no coffee table.

You might put storage baskets behind the sofa and a cheerful painting on the wall.

Found some pix of toy storage behind a sofa:

I don’t think they need to be deep and there’s so many cute options for individual baskets. Depending on the age of the kiddos you might not want lamps, etc. on top of the unit behind the sofa.

Behind the sofa is a great fort making space ;)

Baskets are great for tossing kids toys into at the end of day or having guests over.