Here are some issues I've come across:
In chapter 3, only one player can choose a hero from the altar, then the altar disapears.
Some things are not shared, for example I was playing as blue in chapter 4 and some other player built workshop and it didnt unlock for me.
When a player leaves the food cap increase is not directly changed, you have to build another farm to increase it, for example when you have 14 food max and then you can have 16 food, you have to build another farm even if you already support up to 20 food.
Also it would be nice to be able to share buildings just like the towers. Or make some kind of option to do research in allies buildings. And shared food would be great too. Just one big communism sim.
Increase the difficulty at some parts, we were playing at 8 ppl and some parts and chapters were really challenging (which is good as for myself), some others too easy. I can give you my ideas and elaborate more on this if you're interested. I have quite a few things to share on this.
And I suggest to make some kind of kick command because of trolls.
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Otherwise great idea and take on the campaign we really enjoyed it. Looking forward for the next one.