I would like to see wildlife as an upgrade to the food chain - we have crops, so why not have livestock?

Also, the cave presents the perfect continuation gateway - it could lead to another, previously unaccessable, part of the island where puzzles are much harder to complete.

Perhaps tasks that require many islanders to build (at least two mast builders and two mast researchers, etc). An environment that is more hazardous (like fishing boats that are lost at sea) so that the population is thinned more regularly. This would allow for continual births.

Please make a part two that is based on the completion of part one, and make it a more challenging environment so that the enjoyment of the game can be extended.