Savestate hacking used to be easier because everything in a savestate is uncompressed and raw. Tile graphics, level layouts, palettes, sprite mappings, etc. To

Savestate hacking used to be easier because everything in a savestate is uncompressed and raw. Tile graphics, level layouts, palettes, sprite mappings, etc. To hack a ROM you need to know how to decompress the data, and then recompress your changes. A given game might use multiple compression formats.