I like this game, and enjoy petting the kitties. Overall I don't have a huge amount of notes, but I do have some for the spots you requested feedback on:
Is game clear in what you are supposed to do:
Yes, overall the UI and interactions make sense, and the tutorial clears most confusion.
Does interacting with game feel fun:
Early on, yes, though it does get to a point where it starts feeling a bit dull and repetitious.
Do automation upgrades feel rewarding:
Yes, they do, though, in my opinion, it takes a little long to get it up to a level where the automation takes a short enough amount of time to really matter, as even at level 10 it still took 10-20 sometimes 30 seconds for interactions to happen.
Are any gameplay elements unclear:
No, not really, things made sense from the start, and there are not a lot of gameplay elements so it is easier to make them feel good together.
-R