Yes, you could make it more difficult if animals should collect acorns or die of hunger. For example, if they collect only 80%(4/5) of acorns at the end of one "world", one dies. If they have only 20% acorns(1/5), four die.
That helper-waitress is useless. Why can't she just hang the order on the rope!? No, the cook must drop everything and stant there listening to her talk!!!
it's not interesting to play through the same ores again. Maybe if you limited it to first 10 ores until Prestige 1, next 10 -Prestige 2 and so on. In that case you should recalibrate the prices
I had to read the manual of in-game computer to pass the game. What next? Game developer will make the players read License Agreement and look for hints???
2 Those goal notes like "check in 20 Natives" should be transparent, or user should be able to hide them. I can't see what's going on on 4 and 5 levels
have you ever read about Dyatlov Pass mystery? It's a true story of group of tourists that went to Ural mountains in winter. Sudenly they all got mad and killed each other. Some of them ran away naked and perished in snow. No one knows why that happened.