Another thing filename-wise - the sprite artwork/sound effect filenames help confirm internal names for most (sadly not all) of the bosses. Note that these names might not be final - the Heavy Magician is referred to as Heavy Mystic, for example - but in the absence of anything else to go on it's better than nothing, similar to how most of the names we have for Sonic CD's enemies are simply the names they're referred to by in the internal code. Names found via sprite artwork in this way include: Green Hill Zone Mid-Boss - DD Wrecker (no clue what the DD stands for - any ideas?) Green Hill Zone Boss - Death Egg Robot (actually DE Robot in the filename, but unlike above we already know what that stands for!) Chemical Plant Zone Mid-Boss - Amoeba Droid Chemical Plant Zone Boss - Though no dedicated sprite files exist for this boss, the player/Eggman art related to it is all prefixed with MBM, unlike the unlockable Mean Bean mode for which the art is named Puyo. From this, it can be inferred the boss name is likely Mean Bean Machine, the same as the game it's referencing. Studiopolis Zone Boss - Weather Mobile Flying Battery Zone Mid-Boss - Big Squeeze Flying Battery Zone Boss - Spider Mobile Stardust Speedway Zone Mid-Boss - Hotaru Hi-Watt. Interestingly, if this is the final name it'd also canonise Sonic CD's internal name for the badnik it's based on! Stardust Speedway Zone Boss - Metal Sonic (duh!). Interestingly, the sound effects for the badniks based on the 8-bit Mecha Sonic which appear during this fight are all prefixed SS - as the sounds for Metal Sonic are prefixed MS, the SS almost certainly stands for Silver Sonic, the popular nickname for the original boss and also apparently the name of this badnik. Mirage Saloon Zone Boss - Heavy Mystic (prototype name - superceded by the finalised name Heavy Magician as given in the game manual. All the internal sound files are also prefixed Mystic, so this was definitely the character's name for a period during development). Oil Ocean Zone Mid-Boss - Meter Droid Oil Ocean Zone Boss - Mega Octus Lava Reef Zone Boss (Sonic/Tails) - Heavy Rider, as per the game manual Lava Reef Zone Boss (Knuckles) - Heavy King, as per the game manual Egg Reverie Boss - Eggman's craft is the Klepto Mobile and the Heavy King's upgraded form is the Phantom King. The other upgraded Heavies are all filed in here too, so presumably they're the Phantom Gunner/Shinobi/Rider/Magician per the King's naming here. Interestingly, all the upgraded Heavies' art is named starting PhantomKing, suggesting they may all have been part of a single boss-fight at one point - there's also unused art in the Titanic Monarch boss machine's art showing what appears to be the very top of a giant mech or something, so both fights may have been conceived as being quite different at one point! I know some people said Stealth mentioned some boss/enemy names on his stream - I avoided it at the time to avoid spoilers, so don't know what exactly was mentioned there. For anyone who saw it and took notes - if we combine the info from the stream with this internal data, do we now have a relatively complete list of boss names throughout the game?