Enable the "Level select", "Super Sonic", and "Debug mode". On any stage, get fifty rings and turn into Super Sonic. Change Sonic into the television monitor, then change Sonic back and have him jump to turn into Super Sonic. Jump on the television monitor to have Tails become invincible, then turn into an enemy and put it right on tails while he is invincible. Continuously place the robots there, which will be destroyed because Tails is invincible. You will get tons of points, which add up to extra lives.