Are you open to painting the walls, purchasing new flooring, and/or new furniture, or are you asking what you can do to make this look better while keeping all of these grey elements the same?

I increased the TV screen and added a media cabinet below.

I lowered all your art in order to make your ceiling look taller.

If this is your family/kid hangout then I think it looks fine with what you have. A bigger TV and a console will help with that back wall.

I like it as is. Clean, neat and comfortable. Down the road you can paint and redo the floors. Seems like a waste of money to redo right now, especially if you have young children.