I like the western style and you definitely did a great of using all the right visuals, music and sound effects to really sell it. The top down shooting gameplay is fun. It's cool how you can dual wield revolvers, shotguns, or a mix or both. Having a boss fight at the end is a nice addition too.
The mechanics could be fleshed out a big more though. The concept of mixing and matching dual wielded weapons is neat but quite limited. There's only two different weapons in the game and both have unlimited ammo, so once you get a couple guns there's no reason to switch. This mechanic could have a lot of potential with more weapon variety, plus some ammo mechanics to force you to ditch old guns.