Very good.
I loved all the different spells you can get and the ways you can use them together. My favorite combo was running into the middle of a mob with Holy Armor on and casting Meteor and Lightning once they swarmed around me. :D
A few things that could be made better:
-Upgradeable sword. I know it's been said before, but it's worth saying again. Even if it just rises in strength each level, that would help.
-Satan's Touch seemed to be very weak compared to Ball of God. BoG could kill an entire mob of bosses in one shot, while Satan's Touch only brought them down to low health.
-I would have liked a description of each spell on the skill page, it would have made it easier to decide which spell to buy first.
-Instead of only having an HP bar over enemies' heads, it would have been nice to be able to click on an enemy and see its HP on the bottom/top of the screen in number form. Spell damage could also be added to the skill page. That would help a lot in deciding which spell to use. (For example: Enemy 1 has 1,000hp and Meteor does 100 damage/second for 5 seconds, so it will take two Meteors to kill it.)
-Did every enemy give the same exp? It looked like I got the same exp from killing a boss that I did from killing a mage, which is not cool. If I spend ten minutes firing fireballs at a boss, I'd like to get more exp then if I hacked a mage to death in ten seconds.
-You should put in a Survival Mode, where there's just infinite Waves of enemies. You could put sword and armor upgrades into this mode, too. Maybe even a Regeneration skill that would slowly regain your Health without casting a spell.
Besides that, great game. 9/10!