Editing sprites with assembly information is a lot of work. Not sure if I'll ever get to that. But if you want to change just the tiles that should be doable with a tile editor and an expanded ROM.
Here's the current version. It's a huge hack right now so I disabled a lot of things. Ignore all the random megaman stuff which I haven't converted to castlevania stuff like the icons.
- File -> Open to open the ROM. You can scroll through the level segments with page-up and page-down. Many of the levels have graphics errors in the editor.
- File -> Expand ROM will try to expand the ROM. It will tell you if it succeeds. It's expanded from 1MB to 2MB.
- File -> Save/Save AS will save it. Make sure to save after expanding if you want to try the ROM.
There's also a button to start an external emulator and a menu item for an internal emulator. The internal emulator has a lot of bugs (sometimes the screen moves off the map temporarily, it shakes right now when walking). Make sure to setup your joystick or key settings if you want to try the internal emulator. F1-F10 load state, Shift+F1-F10 save state, space = pause, F12 = start emulator, Escape = stop emulator.
All the decompressed stuff is dumped to $100000 (1MB) and above. I forced all the tiles to be aligned to $20 byte addresses so they should be easy to view and edit in a tile editor. Simon, items, and weapons are still compressed right now. I'll figure out where they are located and decompress them in a future version.
If someone is bored I would appreciate you trying to go through the whole game on an expanded ROM to make it sure it works. I played about halfway through without seeing any graphics glitches or having it hang.https://drive.google.com/file/d/0Bx9gzQZCkH8qTXVOQ2h0bm44MVk/view?usp=sharing