The core idea is good, but skill design is poor. Level design renders non-flying characters uncompetitive. Breath attacks on large characters are aimed too high, limiting their usefulness. As a result, despite the vast list of characters, most are not worth bothering with. I suggest the flying ability be unlocked for all characters after achieving some goal, for example unlocking 30 new characters.
Additionally, status effects are worthless due to the global cooldown. Separate cooldowns for each ability would solve this problem and make abilities more interesting.
Providing "unlocks" for finishing the game to moderate the effects of randomness was an excellent idea.
Fun, simple game. I'm interested to see what you come up with for the sequel.
In this game, Holy is a bit weak since Smite lacks an AoE component. In the interests of variety, I suggest increasing its damage instead, preferably through the passive skills. In a more complex game, the healing might be more significant, but here Holy seems to be the only path that requires much healing.