This is really good Ethan. While I'm a far cry from mastering sculpting myself, I do have on criticism and that is the position of the Giants head. In my younger days I used to spar having been trained in Karate at an early age by a family friend who was a black belt. Although Achilles has a leg up on the giant, the Giant being a seasoned combatant would most definitely still be looking Achilles in the eyes and not down at his ankle or something.
I've seen this in classical sculpture too where the two figures have unbreakable eye contact and I think it makes the piece look more dynamic,,, but again, I'm no expert.