This was fun to play!
I felt that the Instructions on the main page is great, but I felt that it was too much text, and the important bits in it, didn't stand out a lot to me. Just a visual thing, but wanted to let you know how I felt about it.
Some of the Horse SFX didn't really sound like horses. When I pressed retry, I would expect some feedback as well when I restart the game. A little more leeway would be nice for when cowboys arrive on the scene, so that I have a bit more time to run away from them. Like, just pop onto the screen, and wait for a second, and then run after the player character.
Overall, I'd say that this was a very fun game, with great replayability value. It was funny in its essence, and I had a great time playing this!