To be honest, I was skeptical about how fun the game would be, but enjoyed watching you work on stream. Now, I've finally given the demo a chance! (v1.29)
Good:
I wanted to play the tutorial level again to figure out what I could do differently. (And to find that darn secret! Haven't yet...)
You bill this in the stream as an "RTS", and I was skeptical just watching the stream about how much strategy it has. But there were enough potential decision points that felt meaningful to think, "Yeah, I see where this is going."
In any tutorial, you have the tension of what to explicitly tell the player and what they should figure out on their own. The food mechanic felt good here. At first, I thought you had to throw meat at the demons when they got hungry. But then discovered the demons will walk up to you to eat.
However, one thing feels strange. I can walk into a empty house, and see that there's no meat. But demons destroying that house will give meat for...reasons. This is counter-intuitive. Not sure if this needs to be explained explicitly.
To add:
List of keys and controls somewhere. Some other comment mentioned the tab key does something? I never figured out how to sprint, or even knew it was an option until reading other comments.
A pause button. Due to prior gaming experience, I figured Esc would display it, but it's not obvious for a new gamer.
Problems:
In the very starting house, I had a problem opening the door! It's not clear that you need to walk up closer to the door, then left-click. (I tried right-clicking without being close enough, left-clicking without being close enough, walking up to the door and pressing space bar, and walking up to the door and right-clicking before figuring it out.) Maybe the dialog could include the word "left-click" somewhere.
Imagine someone walks out the door, summons their first demon...then makes a sharp right. It's a large area with almost no resources and is the opposite direction of the goal! The demon(s) will quickly get hungry, and it's hard to recover.
The sleep mechanic. On stream, you'd mentioned you want the player to explore the map. But the sleep mechanic almost directly discourages exploration. It feels like I have to stand still and do nothing for 30 seconds every 2 minutes. An idea is that only combat causes demons to become tired (or, simple walking around doesn't increase tiredness so quickly).
The combination of limited food and sleep is an additional damper on exploration. The tutorial encourages the algorithm "If the demons are not tired, beeline towards the next source of meat or portal. If the demons are tired, stay in place and don't do anything." It feels like there's not very much time to explore.
Both times I played, I "destroyed" the keep, but it was confusing to see the end game screen. The first time, demons were banging on the door, without obvious progress. I walked around the keep, got sort of close to the item, and then got the victory condition. The front wall of the keep was still standing.
The second time, I was not very close the keep, chasing around some archers. It went to the victory screen after they all died (I think?). I don't remember if I had collected the reward item in the keep or not. Then, some enemies spawned or respawned 30 seconds after being in the victory screen.
When I get time, will try to reproduce these.
A suggestion here: as the keep is "killed", pause all other action, and point the camera on the keep. As the keep crumbles, the player will know "Oh, I did it...and what is that special item in there?" Afterwards, switch back and let the player grab the "prize".