Pokemon Prism: The tSR Pokemon Game

[Sengir]

releasing pokemon having consequences on the environment (if you release a pokemon with egg moves or TM moves, wild pokemon in that area begin to appear with said moves, or you could potentially make a new pokemon species appear in the wild in an area where normally it doesn't).

Perhaps a Pal Park replacement where you have a list of Parks in the same way the Safari Zone has a list of areas. Each one starts out empty until you release certain Pokemon there where they repopulate. And you would be able to customize them and trade them in the same manner as the Link Safari Zone.

idk, just an idea.