Hey! Thanks for taking the time to listen to my stuff :)
I agree with the shrill-thing. In fact, I feel like the entire mix could be redone with some more focus on the impact of the low end, because the top end does shriek from time to time. I tried to emulate the classic Megaman sound by making it sound not too full sound-wise, because the classic chipset of course couldn't produce full-fledged rock music :P The result is, indeed, a bit too piercing sometimes.
As for the theme, from 00:10 onwards the first theme starts, and from 00:30 the real melody kicks in. The first theme is also accompaniment, so not a very clear melodic theme, but I feel the second theme couldn't be much more melodic :P but maybe I'm misunderstanding your comment? Thanks nevertheless!