This same thread is cross-posted at NintendoAge. I also posted on Reddit a few days ago. Figured you folks at Digitpress might have some interest.

A buddy of mine found this at the swap meet this morning for $20. I walked right by it! He hasn't tried firing it up yet, but the date code puts it a few months before the retail release. My assumption is that it is a final build, but we'll find out shortly. The cart is significantly heavier than a standard Genesis cart. Anyone have experience with these pre-production carts? The seller supposedly sourced it directly from Neverland.

Stage 3-2 footage (Thriller stage music, the original video)



Alternate Final Boss sequence:



Music Test, Stage 3 (aka Thriller)




Pic of the internals (EPROMs):



Here is a list of differences:


A screen with copyright info plays when the game is started. I found a reference to this in https://tcrf.net/Michael_Jackson%27s...lker_(Genesis) described as 'Unused Text'

When you start a game, there's a level select screen allowing you to choose the round and scene.

On the options screen the list of music samples is different, with generic names like 'Round 1', 'Enemy' etc. instead of song title.

There is no score & time screen after you beat a level.

The transition animation between 1-3 and 2-1 is different.

Bombs are always stationary and always explode after 3 seconds.

In 2-2 the two elevators at each end of the level are not synced. If you use one you have to go all the way back to it to change floors.

The 2-3 boss battle is different, there's no magic white dog, just a bunch of the regular dog enemies.

The Round 3 music is Thriller, the full song.

In the 3-2 and 3-3 boss battles you just fight regular zombies, they don't fly or detach their torsos or anything.