Sonic the Hedgehog 2 (Nick Arcade prototype)

The Sonic The Hedgehog 2 Early Prototype, released to the public on Nov. 7, 2006, is a prototype of Sonic the Hedgehog 2 for the Sega Mega Drive/Genesis, which features extremely unfinished zones. This cart, seen in two 1992 episodes of Nick Arcade, predates the more famous Sonic 2 Beta. It was found and sold to drx in cartridge form for $1500 via a community effort.

In this version, only one zone can be normally played : Emerald Hill Zone. The rest of the Zones can be played only through a Level Select code. The level select screen is completely identical to Sonic 1's, and even contains the original Green Hill Zone.

Various tidbits:

• If Sonic runs into a wall with a high velocity, he will bounce back off of the wall. This feature was ultimately canned, but it uses unused sprites that remained in the later beta.
• Green Hill Zone and Labyrinth Zone are both included in the game, but have heavily corrupted tiles. They otherwise play similarly to their original forms.
• Hidden Palace Act 2 has some leftover object placement from Green Hill Zone Act 2. There is a third act, as well, which has water that constantly rises and falls.
• Each Zone uses music from Sonic 1, further proving that Sonic 2 was built off of Sonic 1.
• There is a Hidden Palace Act 3, which has water at a constantly rising and falling rate.

Art Differences

• Sonic and Tails are in different symmetrical designs on the end signpost
• Chemical Plant Zone uses a purple-pink accent in the background instead of olive green; buildings are also much lower
• Seesaws similar to that in the final Hill Top Zone can be seen in Emerald Hill's object debug

Levels

• Green Hill Zone (playable)
• Chemical Plant Zone (playable)
• Labyrinth Zone (cut) (empty)
• Hidden Palace Zone (cut) (playable)
• Green Hill Zone (playable) (renamed to Emerald Hill Zone)
• Hill Top Zone (playable)

Cheat Codes

• Level Select: At the title screen, hit Up, Down, Down, Down, Down, Up, Start.
• Debug Mode: At the title screen, hit C,C,C,C, Up, Down, Down, Down, Down, Up, A+Start.
• Level Select with Debug Mode: At the title screen, hit C,C,C,C, Up, Down, Down, Down, Down, Up, A+Start, wait for demo to start, then Up, Down, Down, Down, Down, Up, A+Start.

Physical Cartridge

(from drx's Hidden Palace)

• 

  Front of cartridge with holographic "Sonic 2" label

• 

  Front of cartridge without cover

• 

  Back of cartridge without cover