A fun little romp. I enjoyed crawling around the labyrinth and killing those little monsters.
A few suggestions for improvement:
1. Music would be a fine addition and help with the immersion.
2. It would be better if the player can see which way he is facing from the character sprite. (The computer knows the facing, but the player can't tell just from looking at the sprite.)
3. The attack animation doesn't clearly indicate the zone of damage. For example, if the player is striking out to the left, the attack animation should indicate that.
4. A map would be helpful, of course.