A variant of tower defense, this one features you, and a bunch of outlaws, trying to stop the settlers from coming through the canyons with variety of units, including rifleman, dynamite chuckers, flame arrow shooters, cannons, and gatling gun. Got this from the Amazon Appstore daily giveaway, though I've tried it previously when it was ad-supported.
The later levels are pretty hard, when you don't seem to have enough firepower to stop them all. The ability for the units to move and pickup chests of "bonuses" is an interesting touch.
The paid version have no ads, and 5 different locations (each with multiple "maps", and each maps have multiple "waves") while free version have ads and just one location.
The longer review is in roundup of tower defense games.
Rating: Try it
http://www.appbrain.com/app/gunsnglory-free/com.hg.gunsandgloryfree (free version)