Advanced Tumbleweed Simulator
Walk over to any editor-placed object. Select "get in ball as driver" action.
Use mouse wheel to zoom in/out. Use move forward/backward/left/right keys to roll the tumbleweed. Press delete to exit ball.
The more you collect, the bigger it gets! As it gets larger, you will be able to pick up larger things (e.g houses)
Not designed to work in MP – it might work, but it definitely won’t look good!