Very cool game! Shooting and abilities are very well done, feels fun. I didn't really notice much difference in enemy movement or abilities with every death. General idea of golem helping you is nice.
Player didn't feel like a boss though, yeah, the golem is helping him, but it does not do that much and without the golem you have the same abilities as the enemy does. I encountered only one bug, it is very easy to make the enemy stuck in the tutorial target, don't think there is any reason for it to stay there after the tutorial.