Damn this game rocks! From the music to the artwork, animation, economy of upgrades, very well done! Only major thing I would've wanted was a prestige mechanic, maybe new characters that interact with existing systems (e.g. maybe someone that rides on the back of the horse auto-firing at fliers, increased horse speed, passive candy income, etc).
And only minor things are some of the gravestones were backwards, and since they have the light angles reverse on them it looks a bit out of place. That and it would be cool to see a little more interesting details in the background behind the trees. Some (very few) of the voice lines were a little cringey; I didn't mind the ones with puns, but others just didn't seem to have a punchline e.g. "neigh, neigh neigh neigh, horse". And lastly make the candy a liiiitle bit bigger as it's tough to click on the ground. Also ghosts seemed to completely stop spawning later in the game?
Anyways, congrats on the great game (and great hand-drawn thumbnail too)!