Wow you're lucky. When I was younger (2004-06), I lived in a 100-year-old house and had a gigantic bedroom and was allowed to use the gigantic spare room. In my bedroom, I had bunk beds, a foosball table, a desk with an old computer on it, two bureaus/dressers/whatever, a dog crate, a small entertainment center where I kept a small TV, a DVD/VCR player with about 25+ movies, a PS2, and like 30 games. Then the floor was covered from wall to wall with Hot Wheels, racetracks, hobbies at the time, stuffed animals, everything.
In the 'play room', there was no furniture except a big cyan metal cabinet, but we had probably about 2in accumulation of more Hot Wheels, board games, etc across the whole floor. Definitely the messiest rooms I've ever had in my lifetime. When my parent's 4th child was born (my 2nd sister), my oldest sister had to move into the play room, but I don't think we missed it that much.