Armets move slowly but have a tough shell, so they take a few hits to kill.
Urchin
Urchins are just like Pinballs.
Froppa
The Froppa jumps out of the water(or lava), hops around, and then hops back into the water.
Fuzz
The Fuzz doesn't hurt you, it just jynxes you(like in zelda), making you unable to use your weapon for a short time or until you exit the room.
Muncher
Munchers walk around biting. They take a few hits to kill.
Rocky
Rockies are invisible as they charge at you. When they hit a wall they'll appear for a moment(this is when you can hit them), then they'll dissapear again while firing stones in several directions.
Rocky (2)
These guys only look like Rocky. A few hits and this slow-moving rockman will be dead.
Squido
Squidos move around anywhere in the room and do nothing. You can kill them with one hit. (try using the Spikes in a room filled with Squidos, it's cool!)
The Froppa enemy is actually a mythological Japanese creature called a Kappa.