Sonic & Knuckles marks its 30th anniversary and to celebrate we take a look at Sega’s unique platform title and show off a wonderful collection. Released on 18th October 1994, Sega were on a high after the huge success of Sonic 3 for the Mega Drive released earlier in 1994. Sonic & Knuckles is technically Sonic 3 ‘part 2’ but has enough fresh content to be considered a standalone title. It’s usually regarded as the final part of the classic Sonic storyline and notable as the final Sonic game developed by the Sega Technical Institute.

The game is set directly after the events of Sonic 3 where Sega’s speedy mascot stops the evil Dr Robotnik from launching the Death Egg into space. After escaping the exploding space station Sonic is rescued by “Tails” and they land safely in Mushroom Hill Zone, the first level in the game. Sonic soon discovers the adventure has only just begun as the Death Egg has crash-landed on top of Angel Island’s mountain. Sonic must now continue his journey to face Dr Robotnik once more and finally destroy the Death Egg.

During the game’s story, Sonic also discovers that Angel Island is the home of the Master Emerald, a powerful device that allows Angel Island to float above the clouds. Due to the Death Egg crashing into the island, it has sunk into the ocean and Sonic must restore all the Chaos Emeralds, and the Master Emerald, to get the island back into the skies.

The other titular character, Knuckles, had been introduced in the previous game as an ally of Robotnik. In Sonic & Knuckles, his story takes place after the events of Sonic’s adventure when one of Robotnik’s creations has survived and is once again causing havoc across Angel Island. Knuckles, the protector of the Master Emerald, must do all he can to stop this new threat.

On the face of it, Sonic & Knuckles appears to be a standard platforming game of high quality but linear gameplay. However, there is another feature that makes this title stand out and offers a unique mechanic not seen in cartridge-based gaming before. The physical cartridge has a slot on the top that allows another Mega Drive game to lock on. This is not just another Sega gimmick either, the device breathes new life into your other Mega Drive games.

Firstly, it allows Sonic 3 to connect directly to Sonic & Knuckles creating one epic adventure. With the two games combined, you can play all the levels of both games together. It allows Knuckles to be used in Sonic 3 and “Tails” in Sonic & Knuckles. This opens up both games further with new areas and features to explore. The other benefit is Sonic & Knuckles takes advantage of Sonic 3’s save feature allowing you to replay individual levels once the game finishes.

Sega had every intention to do this, even during the development of Sonic 3. We now know that Sega felt cramming all the levels and gameplay onto one Sonic 3 cartridge would have made the game expensive. The decision was taken early to split the games over two cartridges but also allow each to stand on their own. It’s a genius compromise to a problem of cartridge memory in the 1990s and gave a choice to players as to whether to spend the extra money buying both or sticking with one.

Plugging in a copy of Sonic 2 allows you to use Knuckles and all his abilities in this game. It’s interesting playing through Sonic 2 as Knuckles due to the new areas you can reach using his climbing ability. The boss fights can be more difficult due to his slightly shorter jump but it gives a new dimension to a game that already offers so much excellent gameplay. Gliding around classic zones such as Chemical Plant or Mystic Cave is a real joy and shows off Sonic’s second Mega Drive outing like never before.

The content doesn’t end there either. Connecting the original Sonic opens up a Blue Sphere game that is essentially thousands of Special Stages the same as those found in Sonic & Knuckles. Finally, if that is not enough, plug in any other Mega Drive cartridge to unlock one Special Stage to play through. It’s safe to say that Sonic & Knuckles is a unique game that epitomises Sega’s approach to trying anything and pushing the boundaries of console gaming, even if it didn’t always go to plan.