I also added a little skeleton variety for fun. There's still no boss or end to the game, but there are multiple stages that keep introducing new enemies, so it should give a good challenge and feeling of progression.
In-game tutorial explains how to play, but here are controls for reference:
WASD to Move
Mouse to Aim
Left Click to attack. Hold and Release to charge your magic attack
Right Hold and Release to Raise Dead. (Or right-click if you have mana)
Spacebar to return to life.
Pick up Mana while dead to boost your magic power and to progress to the next stage.