Once enabled, they behave in the same manner as they do when running on non-Japanese systems. C, C, C, C, Up, Down, Down, Down, Left, Right, hold A and press Start.C, C, Up, Down, Down, Down, Left, Right.As usual, they are entered on the title screen and can be combined by interpolating a D-Pad direction between them. Here, there are separate codes for the pause options and the rest of the debug features. Pause Options: press A to go back to the title screen, hold B to enable slow motion, or press C to enable frame advance.Hold A and press C to move backward one object.Placement Mode: Press B during gameplay.To activate Level Select and Debug Mode, simply enter the Level Select code, push any direction on the D-Pad after the ring sound, then enter the Debug Mode code.įrom here, you have access to a variety of things: The 'Pause Options' (see below) are enabled even if A hasn't been held. After entering the code, press Start while holding A and continue holding A until Sonic appears in the level.

The main requirement for the code is pressing C twice before the final input of Right. While Up, C, Down, C, Left, C, Right, C is the most common version, a shorter version is C, C, Up, Down, Left, Right. International Version & Japanese Version on International HardwareĪnother well-known code. This original level order actually showcases the levels getting more and more mechanical in theme, as Sonic gets closer and closer to Robotnik's Factory.Īgain, codes for the debug mode vary based on console or game region. In the Sonic Jam Official Guide, programmer Yuji Naka explained that this is because Labyrinth was supposed to be the second level, but was considered too much of a difficulty spike. In the original revision, the level order is different from the order in normal gameplay: Labyrinth and Star Light are earlier than they should be, and Marble and Spring Yard are later. One of the most well-known codes in gaming history: press Up, Down, Left, Right on the title screen (three Downs if playing the JP version on a Japanese console), then hold A and press Start. This is actually a crude attempt at a line break, which can be seen by setting your hex editor's bytes per row to 16 and looking at 0x00120 inside the ROM. When playing Sonic the Hedgehog on a emulator, you might have noticed the header has a very large space formatted as:

Sonic 1 title sprite