Definitely like this game. Plenty of insta-deaths on the challenge mode, but that's why it's challenge mode I guess. Hope to see a sequel at some point!
This worked for me, after some trial and error:
Storm mare, Cyclops, Skeleton
Dragon, Gold Dragon, Ghost
It all of a sudden got easier when I switched to that configuration.
Pretty fun game.
For some reason when you get over 5000 points in a level, it keeps flipping back to 4000 when counting.
Other than that, pretty fun. I agree, some music would be cool.