I do think this has the potential to be a good game if the controls were better. Maybe the horse could have been mapped to the arrow keys or maybe the IJKL keys. Trying to control both characters at the same time holding the space and only using one set of direction keys really make controlling this cumbersome. There's also no visual indicator for when you are controlling the horse, which makes the game hard. I also think mapping the space bar to both controlling the horse and teleporting it is a bad idea. Those two should be separate.
Anyways, I'm done ranting about the controls. The pixel art is alright, and the music is actually really chill. The base for a an enjoyable game is there. I'd say to keep on making. You got potential.