Say, I've noticed something: We're pretty much all aware of Knuckles's robotic replication Metal Knuckles, but what about the mech on Sonic Advanced? Is that a new or redone version of the original Metal Knuckles? He looks nothing like the old Metal. Or is this like the same concept of Metal Sonic and Silver Sonic? (Silver Knuckles?) Big fan awaiting your knowledge...
Sonic R = Metal Knuckles
Sonic Advance = Mecha Knuckles

Yes, they are two different robots. --True Red