Beat the game on hard mode with no casualties (er, technically I guess). I really like how much personality you've put into the game with the different kinds of horses and figuring out what different kinds of things they like, and the slight physics interactiveness like penning parasites into corners with rocks is fun. And an appropriately dark finish to wrap it up is nice (is Luci's name a double pun? L-Merr "Elmer", but also Luci-Merr "Lucifer"?)
One technical issue I noticed was that sometimes when horses repeated their phrase, they'd just make a blank white textbox with no text in it, but that's the only problem I could spot.