I like how you presented the game! Even if it's simple, it does communicate, especially appreciate the visual and auditory warning for when a train is approaching!
I did have a decent amount of trouble with getting apples, pulling the donkey only seemed to work if I was touching the donkey directly, and both characters were a little slow, so there was a decent chance that a train would spawn with no way to get both of them off the tracks.
Regardless, still neat! And, I don't know if it's intentional, but I like the touch that the soundtrack fades the farther you are from the donkey - really emphasizes that you need to stay together!