Yeah, I did testing using the gamepad all the way up until the end, so I was disappointed in how the keyboard controls felt. That's a good idea to stun enemies longer on being hit as well as increasing mobility and allowing blocking. And yes, turning the player into a powerhouse to deal with the increasing masses would make for some fun experiences!
As for the sprites, thank the artists on River City Ransom DX! I just took them from the Spriter's Resource page and animated them so I could focus on mechanics over aesthetics. :)