Basically this should have been ported to the DS.
I tried to play through the choppiness, but it just gets to be overwhelming. You'll be rolling along normal, then the game just slows almost to a standstill, not just a couple of times, but all throughout the level. It is evident the GBA couldn't handle a direct port of this game, so I wonder why they didn't just put it on the DS.
I wanted to keep playing to the end, but when it took me ten seconds to jump up and touch the ground again, I just had to turn it off. Even for $15, I wouldn't recommend this game even for the hardcore Sonic fan.