One of the things that put me off about the Gameboy CV games was the slow walking speed of the protagonists. While I understand this was due to the old school Gameboys blurring very badly when *anything* moved, in the age of emulation it's just a pain in the ass.
So I hacked Castlevania - Legends so Sonia moves faster than usual. If you want the boring details of how it was done, it's in the Readme.
I'm currently trying to do the same with Belmont's Revenge, but it's proving to be much more difficult, to say the least. I hope to have it tackled by this weekend, with any luck (I'm hardcore n00bish at z80).
As a final note, it seems that the location I pointed several routines to is *always* $01, but I only went through half the game after doing it. If you find any bugs, please let me know.