Sonic the Hedgehog Pocket Adventure

Sonic the Hedgehog Pocket Adventure
Developer: SNK Publisher: SNK Platform: Neo Geo Pocket Color Released in JP: January 11, 2000 Released in US: November 30, 1999 Released in EU: December 3, 1999 This game has debugging material. This game has a hidden sound test. This game has a hidden level select. This game has regional differences. This game has a prototype article

Sonic Pocket Adventure is basically Sonic Unadvanced. This also marks the second time Sonic appeared on a third-party console prior to Sega leaving the first-party console business in 2001.

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Prototype Info

Developer Mode

Change byte 0x1F of the ROM to 0xFF in a hex editor to enable Developer Mode. When the Sega screen is displayed, press Option to jump to the main developer menu.

An interesting function of the debug mode is that it allows the player to switch between Sonic and Tails by pressing B. Pausing the game no longer causes the Pause banner to appear and it is possible to trigger a free-movement mode by pressing A + B. Most game interactions that would send you to the title screen will send you back to the developer menu, so the only way out of debug mode is to restart the game.

Beginning/Continue

This is pretty straightforward. Simply pick the level with which you wish to start the game, as though it were any other level select screen.

The "Test" levels are unstable clones of Neo South Island Act 1. Test Stage 1 loads, but crashes as soon as it tries to load the first Coconuts, while Test Stage 2 immediately crashes upon load.

The Zone names are largely accurate to the final game. Neo South Island is shortened to "South Island" for space reasons, Aquatic Relix is spelled "Aquatic Relics", and Aerobase is spaced as "Aero Base".

Playing as Tails on some levels, as seen on the right, may result in unintended animations or appearances as the player was not intended to reach certain levels or cutscenes as Tails.

Selecting Special Stage will allow you to choose which of the six Special Stages to play, alongside two test Special Stages. Test Special Stage 1 is a very short stage with only two checkpoints to get a Chaos Emerald (need 10 and 20 rings respectively), while Test Special Stage 2 is an endless stage testing various ring and mine formations. Test Special Stage 2 can only be exited by restarting the game. Completing the other Special Stages kicks you back to the level select.

Go To Room

This will take the player to the puzzle, duel, and options screen. Exiting this menu will kick the player back to the developer menu.

Direction

Allows the player to see various cutscenes throughout the game:

• OPENING: The opening sequence to the title screen. The game hangs after pressing A.
• ENDING_1: The bad ending.
• ENDING_2: The good ending.
• TITLE_LOGO: This is meant to load the title screen if a button was pressed on the SEGA logo, but it hangs the game at a black screen.
• CONTINUE: The continue screen. Continuing or waiting until the timer hits 0 kicks you back to the Direction screen.

Sound Test

Opens up a simple sound test, clearly more developer-facing than the fancy animated sound test players can unlock on the Game Options screen. On the right, it states where certain tracks/SFXs originate from, particularly their sound test codes from past Sonic games. There also appears to be two tracks at the end of BGMs and SEs named "ED1" and "ED2", which are stubs that doesn't play anything.

Debug Option

A bit more difficult to understand.

• DEBUG DISP - Toggles the display of X/Y coords of the player in the HUD.
• ATK DISP - Toggles the display of hitboxes around destroyable objects (Enemies, Monitors, etc.).
• BDY DISP - Toggles the display of hitboxes around the player.
• MUTEKI - Toggles invulnerability for the player (can't be hurt).
• ALL CLEAR - Toggles a full savegame.

(Source: Sonic Retro)

Regional Differences

To do: Is this everything the region changes? The text is all in English regardless.

Sonic Pocket Adventure uses a single multi-region ROM but varies some details based on the console region.

Photo Pieces

Every Zone in the game features a number of hidden Photo Pieces which can be arranged into character artwork in the Puzzle Room. Oddly, the "Tails"/Miles naming seems to be inverted compared to what would generally be expected, and Sonic's arms are miscoloured in one of them.

Japan	US

Time Attack Name

When first entering the "Time Attack" mode, one must beforehand enter a name which will then be saved whenever a new time record is reached in the game. On the Japanese console, you can use katakana and hiragana in addition to alphabetic characters. On the International system, it's only the latter (obviously).