Cool game! Well scoped. Progressive difficulty. Nice risk/reward leaving the merchant to collect coins... I presume that also connects to the theme? Good feedback when being hit/hitting enemies. Took me a few rounds to get into it. I was a little confused about how to build walls and didn't realize the gold circles on the level were coins. One that was out of the way it was smooth sailing though!
I like the idea of a merchant charging you to save his life. Gotta question his motives as all his wares revolve around his protection.