Cool idea, but needs some work on the gameplay.
I´ll start with the good first :
The story was cool, not very original, but cool anyway.
The graphics were lovely, I liked the "shadow" look you gave to everything.
The overall concept was very well planned and designed, it´s you and your horse in a race against the world.
BUT the bad is very bad actually :
The attacks don´t feel right, at all. The attack animations are akward and innacurate, a milisecond difference in timing even (specially) when jumping, allows the enemy to hurt you EVEN when you hit them, this became really annyoing with the zombies and got me cursing very loudly. You can´t make an attack animation last for 2 seconds, at least not in this game.
The other annoying thing was the fact that enemies actually stop you when you get hit, Maybe you tought of this as a "difficulty" that was worth adding; but in practice, when I´m riding a horse and a bat bites me, a wolf tries to bite my horse, or heck ... even if a zombie stands in my way with his "almighty hand of death", My horse would run over them like if they were not there.
It´s VERY frustrating to be stopped when you run, specially when that strange demon comes from out of nowhere and beats you to death, just because you were in the "recovery lag" that happens after a zombie stops you ...
Think about this, you should be able to run over enemies, at the cost of health if you want, but RUN OVER THEM.
Congrats anyway on a well-done game, hope to see it get better.
Good luck.