I liked the concept and most of the gameplay was fun. I just noticed some things: The guards couldn't hit you if you just mashed the attack key on them. The tank enemies would only fire when you were right next to them and couldn't be dodge if you wanted to actually kill them so I just treated them like obstacles instead of enemies. Also, there was a time when I lost all of my health and then picked up a heart before my sprite was destroyed and I was stuck in a limbo where the game removed the character, but still thought I had health and I couldn't do anything.
The was a fun little action platformer that fit the theme really well. Good work.