This is really cool! It was a bit confusing at first and I didn't understand my cats were hungry and would die the next day from it, but understanding some stuff it was actually quite fun. Still uncertain how the upgrades and cooldown for resource gathering work, but I can imagine playing this for hours!
I struggled so much with the hunger symbol! I had 3 different types and went with that one. Originally wanted a whole character sheet per cat to show each cat's stats, but that quickly got shoved into the "out of scope" box.
The resources/upgrades seems to be the most confusing hurdle to learn OOF 
Essentially,
Placing each resource (pond/tree/mine) takes 2+ days to grow before they can be used. If a resource is placed on top of an existing resource of the same type, it will upgrade that resource after 3+ days or so - which is where collecting Spirits from ascending cats can really speed things up with Fast Forward.
The upgrades are kind of funky. Some upgrades allow 5 cats to gather on the resource instead of the base 3. Other upgrades changes the material that's gathered.
THANK YOU FOR PLAYING AND THE FEEDBACK COMMENTS! It really helps me know the spots that need refinement!