I really like the graphics, the sound effects were alright, if a bit too heavy on the bass. I also really liked finding weapon and health upgrades. I also really liked the slow player, since it helped portray a sluggish powerhouse, like a final boss would be.
The game could use a bit of polish, though . I didn't really feel the weapon upgrades' power until late in the game, and your starting health is kind of low, given that you can be two-hit killed by the second enemy introduced, the boar. The armored goblins also were kind of confusing.
In addition, while I love the concept, I wish a lot more were done with the theme? It felt more like a traditional platformer, especially given that the enemies in the game were more traditional goblins and so on. Maybe give the player a minion mechanic, or something?
Overall, the game was still pretty good, and I'd love an expanded version!