For et kortere spil foreslår designeren, Chad Jensen:
If you want a shorter game, I'd suggest the following:
1. Remove the Intelligence, Parasitism and Omnivore cards from the deck and put them back in the box. This will shorten the game by 3 card plays (generally 1 turn) as well as making sure nobody gains extra pawns that tend to lengthen the game.
2. You may also wish to remove the Immigrants card, since the second option on that card will be more or less invalidated by the removal of the other three cards.