I won’t be participating in this jam but I have an idea anybody can use.
Setting: A Tropical Paradise Island
Objective: Pave paradise and put up a parking lot. Attempt to pave as much area as possible within the time limit while dodging obstacles.
Metric: At the end of the round, you are scored by the number of unknown species and rare ecosystems destroyed. You didn’t know what you got till it was gone. You are a horrible person.