The graphics look simple, but nice. I like it.
The screen effect every time an enemy dies felt too much for me... I was playing by closing my eyes and it still hurts sometimes.
I think it would make more sense to me if the colors of the enemies represented how much life they had.
And I missed the auto-atk by holding the atk button, and a bigger enemy to change things a little bit some times.
Overall it was interesting and a little fun.