In Carnival Night Zone, there is an infamous obstacle known as the "barrel" - a red and white tube that moves up and down depending on what direction is pressed on the control stick, but is animated in a way that makes it appear as if you have to bounce on it to gain momentum - this obstacle has caused a lot of grief to Sonic fans playing the game over the years, and as a result Sonic 3 game designer Takashi Iizuka and lead programmer Yuji Naka officially apologized for the barrel at the Summer of Sonic 2011.