This game has some amazing artwork and design. I love the idea of it.
There are some problems I noticed. I rated the game highly so I bring these up out of love for this game:
On the title screen, if you mouse over the how to play button, you have to go over halfway up onto the play button to press play, otherwise, you'll go to the how to play menu. Same for the exit menu. The button stays selected if you move your mouse quite far above it.
For the fire warlock, the cards which just deal damage to you look like they say they "deal damage too you" since there is a bit of flame next to the "to".
I would like something to keep track of how many cards have been burned/destroyed.
Showing the ending life totals at the end of the game would be really helpful. I ended the game by healing the fire warlock and suddenly it went to the win screen so I couldn't see the ending life totals.
The card which allows the purple warlock to heal with its ability instead of deal damage doesn't really do anything. Either way, it changes the difference in life totals by the same amount.
The grammar on many of the cards is off.
Overall, the isn't a ton of thought which goes into how you play each turn since there aren't many variables. However, overall, this is a great game which fits with the theme incredibly well. I'd love to see how this could be expanded upon.