In Sky sanctuary zone the air that keeps you floating where knuckles jumps on the button and extends the bridge is missing so you just die. Mushroom hill zone act 1 you fall instead of flying in , Layout is different.
Just to be sure: Sonic 3A = Sonic 3 (the one we got) Sonic 3B = Sonic & Knuckles Sonic 3C = Sonic 3& Knuckles on one cart
Lava Reef Act 2 is missing a lot of sound effects -- the flame spewers, the twirling ladder things, etc. There's no music change for when Knuckles pushes the rock onto you. The resulting scene change plays HPZ music again, and the boss music doesn't start until the actual boss fight.
There's no transition ending to Sky Sanctuary Zone Act 2. Death Egg Zone is missing a lot of sound effects.
LRZ2 is a dead-end. The rock you're standing on floats to a nearby rock bridge you can jump on, which leads to the tunnel that WOULD go to HPZ, but the level transition doesn't kick in.
In Sky Sanctuary, there is no score screen after beating Metal Sonic and the sequence of running up the collapsing tower isn't implemented. You just go right to Death Egg.
So... I'm not quite sure this is worth spending my first post ever around here, but I just had to mention the first thing I discovered while messing around with this proto. It seems like the Icecap zone glitch is there, but a little different from what we've seen on the final version: Tails is the one to get affected by it, rather than Sonic. Anyway, here's a screenshot of just how it looks like.
Seems like Knuckles can jump higher and also that hitting a power-up in LRZ with the end-of-level sign yields rocket power-up that lands on the bottom of the rock platform (go forward once act 2 starts and then go back).
Ok drx can you post the level select codes? There are some levels you can't acess via level select...
Seems like flying battery wasn't fully complete. Here's the same place on the proto and on the final version of the game.