Blue Sphere

Blue Sphere Starting Screen.

Blue Sphere is the game created by locking on Sonic the Hedgehog to Sonic & Knuckles. The name Blue Sphere comes from the name shown in its listing in Sonic Mega Collection. It is a compilation of "Special Stages" in the same style (and engine) of the ones featured in Sonic the Hedgehog 3 and Sonic & Knuckles, with a total of 134,217,728 levels in all. However, after level 128,016,000 some of the previous levels begin to reappear. After completing all 134,217,728 stages it restarts from the beginning.

The levels in Blue Sphere are slightly different than the special stages in Sonic the Hedgehog 3 and Sonic and Knuckles. In Blue Sphere, the ring counter decreases rather than increases, and if the player collects all the rings and blue spheres in a level, a "perfect" score is awarded and are a screen showing the stage's difficulty shows. Then the player is advanced 10 levels. Each time the player completes a stage, a 12-number password is given for that stage. Also, each stage has a difficulty level assigned to it, represented by an icon. There are 13 difficulty levels in all. Difficulty is assigned based on the number of spheres in each region of the stage's map, so some level 13 stages might actually be less difficult than level 12 or 11.

The "No Way? No Way!" message that scrolls across the screen at first seems to inform the player that the game attached is not Sonic the Hedgehog 2 or 3. Pressing , , and simultaneously brings up the main screen on Blue Sphere. When at the main screen, pressing , , or allows the player to switch characters. However, the player cannot play as Tails alone or as Sonic with Tails following like in Sonic 3 and Knuckles.

A single Blue Sphere stage can also be created by locking on Sonic & Knuckles to any other Sega Mega Drive game. The stage layout is produced randomly from information in the inserted cartridge's ROM header, along with the stage's 'code' for use in the full Blue Sphere game. Note that playing these levels via a game with battery back up will erase saved games. Also note that this won't work with games made after Sonic & Knuckles was released. There are also some instances of games made before Sonic & Knuckles not working, such as Phantasy Star IV. Also, if locked-on with a game that would cause the combined ROM to be larger than 4 Megabits, Sonic & Knuckles will be booted instead of blue Sphere.

List of icons by difficulty level
Each difficulty level contains the icon of all difficulty levels below it.

1. Nothing
2. Sonic
3. Tails
4. Knuckles
5. Robotnik
6. Mecha Sonic
7. Eggrobo (flying)
8. Chickens
9. Squirrels
10. Rabbits
11. Master Emerald
12. Sonic & Knuckles logo
13. Sonic turns into Super Sonic

Unofficial Pro Action Replay Cheat Codes

Code	Description
FFE443:00	All Rings Collected

Also Released for

• Sonic & Knuckles Collection for PC (1997)
• Sonic Jam for Sega Saturn (1997)
• Sonic Mega Collection for Nintendo Gamecube (2002)
• Sonic Mega Collection Plus for Sony Playstation 2 and Microsoft X-Box (2004)

External Links

• Blue Sphere Password generator