Sonic the Hedgehog (16-bit)

The first Sonic game, it starred just Sonic and Dr. Eggman. It was a simple sidescroller, where Sonic could curl up into a ball, whereupon if he hit an enemy, it would usually be destroyed. Sonic's jump was also a vital part of the game, as it was his main attack.

Each Zone featured three "acts" or levels each following the same theme as the last.

Levels Green Hill Zone (3 acts) Marble Zone (3 acts) Spring Yard Zone (3 acts) Labyrinth Zone (3 acts) Star Light Zone (3 acts) Scrap Brain Zone (3 acts, the third of which parallels Labyrinth Zone) Final Zone (1 act)

Release Dates European: 23rd June 1991 US: 23rd June 1991 Japanese: 26th July 1991

Act 3 of Scrap Brain Zone used the same tiles as Labyrinth Zone, just recolored. It is believed that Scrap Brain 3 was originally Labyrinth 4.

Note: in cheat codes, a + signifies that the buttons should be pressed simultaneously.

Cheat Codes, U version:

From title screen

Zone Select: U D L R A+Start, select zone

In-level Functions: U C D C L C R A+Start, hold A until Sonic appears

Zone Select + In-level Functions: U D L R U U C D C L C R C A+Start, select zone, hold A until Sonic appears (the extra U is to force the cheat detection code to reset itself)

On all codes containing C's, the C's can be input anywhere during the sequence.

Cheat Codes, J version:

From title screen

Zone Select: U D D D L R A+Start, select zone

In-level Functions: U C D D D C L C R C A+Start, select zone, hold A until Sonic appears

Zone Select + In-level Functions: U D D D L R U U C D C L C R C A+Start, select zone, hold A until Sonic appears (the extra U is to force the cheat detection code to reset itself)

Hidden Japanese Credits Screen: C C U C D D D C L C R C, hold Down+A+B+C while demo starts

On all codes containing C's, the C's can be input anywhere during the sequence.

In-level Functions, all versions:

Debug

Press B to toggle normal and debug mode.

Press A to advance forward through the debug object list.

Press A+C to advance backwards through the debug object list.

Press C to place the selected object at the current coordinates.

Current coordinates are designated by the top line of hex digits in the HUD.

Viewport coordinates are designated by the bottom line of hex digits in the HUD.

Slow-motion/Restart - during pause

Press A to fade to black and restart from the "SONIC TEAM PRESENTS" screen.

Press and hold B to enable slow-motion (it is currently unknown how many frames per second this advances).

Press C to advance one frame.