I have to admit; I don't remember everything about the combat since last time I played.
- Never underestimate sound effects. They make the game come to life.
- Make impact frames so that people get feedback when they hit or don't hit something.
- Have the combat interact with the environment. Blood splatter, screen shake, etc.
Gameplay and functionality is always no. 1 priority, but is useless unless the player feels these things.