The game is broken up into levels and each level has a several stages where you'll need to kill three or four monsters to move on to the next stage. In the final stage of each level, you fight a boss, which often takes a number of hits to kill.
What keeps the game interesting beyond the storyline are the different viewpoints offered on different levels. The first level plays like a 2D side-scrolling game, and while shooting at demons, you also need to tilt to move your horse out of the way of incoming projectiles. In the second level it moves to a top-down 2D view where you'll fire shots in the same way, and tilt to move side-to-side on the road. These top-down levels also add additional challenges that have you battling changing winds as you shoot arrows. The thing that impressed me is that A Ride Into the Mountains is really a simple concept, but the gameplay variations from level to level managed to keep my interest.
The only issue I had with the game was with the controls, and it was especially true on a smartphone. As you play, you need to be ready to shoot in all directions, which ends up meaning you'll often switch hands to take your shots to keep them out of the way of the action. On a tablet this isn't much of a problem, but on a smartphone it can get pretty crowded, which made me lose more than a few battles because I couldn't see everything on screen. In other words, it does work on your smartphone, but if you have the option, I would suggest a tablet.
Even with the somewhat complicated controls, A Ride Into the Mountains is a great game for how the developers were able to create such an intriguing storyline with such simple graphics. In the end, for something a little different from the usual fare, this game is a great buy for only 99 cents, but I think it's much better to play it on your tablet.