a couple of friends streamed Blaster Master recently, and one of them mentioned a cancelled (and undumped) Vs. arcade version of the game. this prompted me to check out the TCRF page, which had some stuff added to it since the last time i checked it, including some unused text only present in the European version. i had a feeling there might be more, so i popped open my dusty hex editor and FCEUX, and uhh
it turns out the European version was built from the unfinished arcade version?? there are a bunch of orphaned routines and associated data that would have handled coinage, rendering the score and number of credits to the screen, and a variety of other things. the credit counter reads an otherwise unused RAM address and shows either 0-99 or "FREE PLAY" (when set to $FF), and... well, that's it, really. it's all very incomplete; the "368" at the top of the screen is actually placeholder text and is stored in the ROM as "$368", which appears to be the RAM address where the score would have been kept in the final version. unfortunately, no graphics data, screen layouts, or anything else of real value seems to remain from this currently lost arcade build, and it doesn't seem likely that we'll be getting a ROM dump any time soon, if the other lost Sunsoft Vs. games (Lionex, Wing of Madoola) are any indication :(
it often feels like the NES library has been picked clean of interesting discoveries, but every now and then something like this comes along and proves me wrong. i guess we gotta start digging a little deeper.