From a gameplay perspective, the upgrade that increases your max stamina is way too costly for the return it gives. Essentially it's +2 stamina every time you sleep. The problem with that is that you can just buy tea for 2 coins instead, or forage some berries, both of which are better options and they can be consumed anywhere. Ofc when there are more areas the stamina is also going to get a way bigger purpose, needing a larger base capacity to do stuff. Just saying that rn there isn't really a point in getting it with how short this demo is.