Wow, I just quickly wanted to check it out and got stuck playing the whole evening and actually can't wait to fire it up again. Truly excellent work!
Playing right now :D I'm wondering though if I hit a few bugs, because the professional training doesn't seem to work? It feels like it has about a big a fail rate as self-training and the fee doesn't get deducted (but I'm also not sure what it does exactly, what being circled means or how it affects the game).
The other thing I noticed is that the hours on the working horses don't seem right, it will often say it'll return in 0h, but then it takes 3-4 for them to actually come back.
Otherwise, the only nitpick I have is that I wish when I backed out of a menu, that I returned to the previous one, not back to the farm screen from where I have to open it again, that would make navigating a bit easier. And maybe a little icon next to the horse's name in the selection screen that I can see which one is there and which isn't without trying to open them all and see if they're here right now.
But yeah, it's a surprisingly fun gameloop, kinda reminds me of the kind of games we used to have on our graphing calculators in school, so I'm enjoying it greatly :D