Connect the 1994 Sonic and Knuckles cartridge to the 1992 Sonic the Hedgehog 2 cartridge and insert them into the Sega Genesis and you get this mouthful of a title: Knuckles the Echidna in Sonic the Hedgehog 2. The combination of the two games inserts Knuckles the Echidna into the levels from Sonic the Hedgehog 2. All of the old Sonic 2 elements remain intact, from enemies to badniks to power-ups to bonuses. There are several minor changes that do not effect gameplay, such as the title screen for each level is green and red instead of the usual red and blue, plus Knuckles's shield is grey instead of Sonic's blue one. Furthermore, Tails is not present in the game at all and neither is the two-player mode.

Replacing Knuckles with Sonic changes the mechanics of the levels ever so slightly. Knuckles cannot jump as high as Sonic, but he can climb walls meaning that he can access shortcuts and 1-ups that were previously locked away. Our hero controls just as he does in Sonic and Knuckles and Sonic 3 and Knuckles, so there's no learning curve to overcome if you've mastered his character elsewhere.

Just as Sonic and Tails traversed these levels in Sonic the Hedgehog 2, so does Knuckles in this version:

  • Emerald Hill Zone
  • Chemical Plant Zone
  • Aquatic Ruin Zone
  • Casino Night Zone
  • Hill Top Zone
  • Mystic Cave Zone
  • Oil Ocean Zone
  • Metropolis Zone
  • Sky Chase Zone
  • Wing Fortress Zone
  • Death Egg Zone

The half-pipe bonus levels are also along for the ride, although this time around the rings that must be collected are placed in more reasonable places, making collecting enough to earn a Chaos Emerald quite simple. Knuckles can collect all seven Chaos Emeralds to become Super Knuckles.

Knuckles the Echidna in Sonic the Hedgehog 2 was included in 1996's Sonic Jam for the Sega Saturn as well as the 2002 Nintendo GameCube release Sonic Mega Collection where it's locked away as a hidden game that is unlocked after playing Sonic Spinball and Sonic the Hedgehog 2 twenty times each. It should be noted that the game isn't considered part of the official Sonic the Hedgehog continuity and is just for fun.

Playing the game