Abilities to alter their environment (although not trying to go too far as to turn into a Minecraft/farming situation, rather optimizing an island for convenience...) such as removing rocks, planting trees/shrubs/grass/cacti, permanently removing trees/shrubs/grass/cacti, dig new water streams, build new blocks of land. Expanding on that, having more items they can climb on (love the tree stumps), allowing more vertical mechanics.
Lastly, might be far reaching, connecting islands together, allowing animals to travel back and forth? The plot twist; if animals are left on an island while player is toggled to different island, they will be able to act freely (gather food, breed, move around). Ultimately revealing a global map of all the discovered islands would be neat. Thanks!
