Achilles: AD / arrows walk · W jump · S block & pick up spears · J or T swipe · K or Y kick. Forward + swipe = lunge (or throw the spear).
Warriors: walk, J attack/shoot, K kick (no jumping or blocking). The boss also jumps and blocks, and picks its specials with toward Achilles + J, S + J, W + J. You join the fight each time the game spawns an enemy (you get priority over the computer). 1–4 choose your next class. Enemies have 20 health, Achilles has 100 and 5 lives.