First off, sound effects are messed up. The floor bombs play badnik destruction noises, and the hooks make the sounds that switches make. Skates don't make any noise at all, most of the fire shooters don't make any noise, and the magnet things don't make any noise either
This area is missing enemies, hooks and rings in the beta
This area has bombs added
Rings were added to this area
The floor that appears preventing you from backtracking from this point isn't there in the beta
In the final, they added a monitor here.
They added the Tails-only rings in the final at this spot
In the beta, many of these areas with the two magnetic platforms inbetween a set of spikes have another platform in the middle of the spikes that is removed in the final. Even though the platform is there, the spikes still hurt you if the platform isnt raised.
Monitor change
This isn't here in the final, rather, the spring is at the top of the ramp, right before...
...here, where they added some goodies in the final
This area is bare in the beta, missing that annoying elevator thing that crushes you, and the switch that opens the door.
In the elevator area after the above, the elevator can take you all the way up into the ceiling. This kills you in the final, but not in the beta.
Collapsable platform is missing.
This area is missing a lot of stuff. Those ball things, enemies, rings, the whole works.
Enemies missing here.
And here.
This door is broken in the beta. In the final, the switch opens both doors. In the beta, it only opens the front one. You need to either use debug or find another route.
Another one of those platforms in the spikes
Spikes added here
This area is strange. The switch at the top will open the bottom ledge, rather than the switch at the the bottom. Instead, the switch at the bottom causes a platform to come out the right wall to allow you to go to the top area to hit the switch in case you missed it.
The background begins to break a bit here, where the're some missing platforms that crush you.
Spikes are added to the side here
The background before the boss fight can mess up here in the beta. Also, these monitors aren't there in the final.
Rings and a spring added in the final.