To do: A lot of work on this page, document as many layout differences as possible, dump and add level maps.
As the only other zone in this prototype (along with Green Hill Zone) with three complete Acts, Marble Zone is in a mostly functioning state. The key word here is "mostly"; this version of Marble Zone is considerably more difficult than what it ended up becoming.
Crushers are glitchy. The player can get killed by entering one too quickly while it's opening.
Act 1
Prototype
Final
The three rings at the beginning are absent and instead, you have a Buzz Bomber, which will kill you if you don't move out in time. It should be obvious why that was changed.
Prototype
Final
Since the Caterkiller wasn't implemented yet, Spikes is used as a placeholder instead. Their locations are also different.
Prototype
Final
The section with crushing pillars is missing its rings.
Prototype
Final
There's only 'one' Batbrain near the first "push the block onto the switch" part...
Prototype
Final
...And the aforementioned block is also much further out to the left.
Prototype
Final
Just after that, a crusher moves from the wall, rather than the ceiling.
Prototype
Final
Instead of the first checkpoint, all you get is a set of spikes. Lovely.
Prototype
Final
Act 2
The breakable blocks don't grant points yet.
Prototype
Final
Start of Act
Prototype
Final
Two Spikes enemies were replaced with Caterkillers, additionally, a 10 Ring Monitor was removed.
Prototype
Final
This Pillar section was changed from a fairly simple physics puzzle to just hitting a switch.
Prototype
Final
In the section that has the enemies with the spring into the lava, there are 3 Spikes enemies where there are 2 Caterkillers in the final.
Act 3
Prototype
Final
Prototype
Final
Three rings were removed from these pillars at the start.
Prototype
Final
This secret room under the incline contained three ring boxes before it got replaced into an alternate path.
Prototype
Final
This 1-UP Monitor got replaced into a Shield Monitor.
Prototype
Final
An extra fireball spewer was removed and some were moved.
Prototype
Final
The end of act 3 lacks a boss to fight, but it does have a goal post, making it the only other completable zone in the game
