Hello, you have 24 seconds to create the map (12 & 12), You must edit the map with the mouse to avoid excess trash from Inconsiderate Campers.
Then place trees and stones on which they bounce to prevent progress.

These Inconsiderate Campers, they leave trash, lots of trash ...
Look for the different bags to add waves (as long as it is not the last) and points.
Remember that two or more garbage bags are canceled if they are close, so you can miss out on these different bags

You have to adapt because they appear from random directions.

Good luck, and remember you can always get better... or get worse.