Not sure if it’s too early. Running out of ideas of what to do.

Add the following rule:

At the end of 10 rounds (after all other effects conducted, before “round 11” would begin), one island will be declared the winner. That island has to have the highest (Land*Foliage*Animal Biomass) amount tracked in the table, where “Land” is the highest number they have under “Land”. This does not count the NPC island stats. If multiple islands are tied, Mana is the tiebreaker. If multiple islands are still tied, then the game is extended by one round (ad infinitum until one winner can be declared).