I spammed Shock Wave.
I really found it enjoyable. not exactly challenging but a good base to be worked on. I liked how pikario ran and spamming 4+ attacks at once was neat. :)
It's a neat idea, an a nice start, but definitely requires some refinement. All you have to do is stand in the middle of the screen and spam Thunder, and you can beat the game with only maybe getting hit once or twice by the boss, and not at all from the normal enemies. The attacks should be a bit more diverse, and less broken. Otherwise, it's an amusing concept.
I spammed aura and dark pluse :3