With Yalla yalla!
I won't lie, I am pretty much OBSESSED with crate installations. I have a whole library folder chock full of these types of projects, and this won't be the last one I share. Crate constructions just seem like that sweet intersection between do-it-yourself, creative reuse, budget-friendliness, and cool. Plus, you'd be surprised how sturdy these structures can be once assembled.
This installation stacks vegetable crates and tops them with OSB to create a walking surface. It is used more as a display space than a play space, but I can only imagine re configuring the whole structure to be lower to the ground and good for jumping around on.
TAKE AWAY IDEA
Use crates! There definitely needs to be more experimentation in the world of pop-up playground/temporary structures with crates. They are cheap, easy to move around, and, again, surprisingly sturdy when clustered correctly.