If you experience audio lag when playing the web version on PC with Firefox, please try another browser like Chrome/Opera/Vivaldi, or download the standalone version.

If you experience audio crackling when playing the web version on mobile with Chrome/Opera/Vivaldi, please try another browser like Firefox or download the standalone version.

The 8 Pico Emeralds have been scattered! Sonic arrives on Pico Island, ready to collect them all!

pico sonic is a partial demake of Sonic the Hedgehog 3 made with PICO-8. It features a simplified version of Angel Island Act 1 with some tweaks. Various classic Sonic games were used as reference, including the 8-bit games (Game Gear and Master System), which have sprites closer to PICO-8's resolution and color palette, and the GBA titles, which have more clear-cut graphics.

The project was started as a personal challenge and was meant to be a fully-fledged fan game, but I eventually dropped many features to focus on Sonic's main movements and the exploration of the stage. Consider it a technical demo with some exploration challenge.

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Disclaimers

Fan game

pico sonic is a fan game distributed for free and is not endorsed by Sega. Sega Games Co., Ltd owns the Sonic the Hedgehog trademark and copyrights on the original assets.

PICO-8

The game runs on a patched version of PICO-8 that doesn't have the original token count limitation. Therefore, the .p8 and .p8.png carts cannot run on a vanilla PICO-8 binary. However, I do respect the (compressed) characters limit for each cartridge.

Distribution

This game is only meant for distribution on itch.io, SAGE forums and the repository’s GitHub (see links below). If you find a copy (generally the embedded web version) on a different website, this is an unauthorized redistribution of the game. Make sure to play the latest version on itch.io.

External links

• SAGE (Sonic Amateur Games Expo) 2021 entry
• Source code repository (GitHub)

Features

Version: 7.0

Sonic has all basic movements from Sonic 1 but lacks look up and double-jump powers (there are no item boxes for shields anyway).

There is also no timer (sorry speedrunners!).

More info on the repository page.

Content

Title menu

• Splash screen
• Attract mode (wait until end of music)
• Credits
• Cinematic + stage intro before stage starts

In-game

There is a single demo stage which covers the first part of Angel Island Act 1. Scale is close to 1:1, but Sonic is slightly smaller (relatively to the environment) than in the original game.

The game uses a custom map "streaming" system to allow a bigger map than PICO-8's standard tilemap. There are no enemies, hazards, rings nor item boxes. Rocks are not destructible.

Some enemies have been replaced by static obstacles, and most importantly some items have been replaced by emeralds that can be collected to make the stage more interesting.

Stage gimmicks:

• Spring
• Loop
• Launch ramp

Controls

You can play with keyboard or gamepad. If you're playing the web version, you can click on the gamepad icon on the right of the frame to see the virtual gamepad input mapping.

Here is the full input/action mapping:

Keyboard	Gamepad	Action
Left/right arrows	D-pad left/right	Move
Down arrow	D-pad down	Crouch, Roll (during run)
Z/C/N	Face button up/down	(PICO-8 button O) Jump, Spin Dash (during Crouch)
X/V/M	Face button left/right	(PICO-8 button X) Cancel (menu)
Enter	Start	Open pause menu
Alt+Enter		Toggle fullscreen
Ctrl+R (standalone only)		Restart current cartridge (title, intro, stage or stage clear sequence)

If you gamepad mapping is not correct when playing with the native PC binaries, you can customize it with SDL2 Gamepad Tool and copy-paste the configuration line into sdl_controllers.txt in PICO-8's configuration directory. For instance, the Logicool Gamepad F310 had Open PICO-8 menu mapped to Right Trigger, so I remapped it to Start instead.

Pause menu

In the pause menu (toggled with Enter/Start), if you are in-game, you can select the following options:

• Warp to start: restart stage from beginning keeping collected emeralds
• Retry from zero: restart stage losing emeralds collected so far
• Back to title: go back to title menu

Known bugs

• Character can get stuck inside ground when landing on curves and inside loops (fixed)

Known technical issues

• The game cannot run on a vanilla PICO-8 because it relies on several custom binary patches
• The player cannot control the character until the stage intro is over (player can now skip stage intro by pressing O or X)
• The game pauses to switch to another cartridge, esp. at the end of the stage intro (only memory reload has been patched on PICO-8 to be instant)
• Web version: audio lag on Firefox on PC, audio crackling on Chrome (and other WebKit/Blink browsers) on Android
• Web version: high-pitched sounds in BGM do not convey the same as in desktop/cartridge versions

Known design issues

• The stage feels a bit empty and too big due to the lack of items, enemies and hazards
• Scaling is slightly inconsistent as the tilemap is 1:1, but the Sonic sprites are slightly smaller than they should be (rocks in particular look very big)
• Some ugly sprite / sprite transitions and SFX too far from the original sounds

Releases

You can download the latest release below, and any released version on the repository Releases page. If you own PICO-8 and want to run the .p8 or .p8.png cartridges directly, download the pico-sonic-p8.zip or pico-sonic-png.zip respectively. However, please note that you will need a patched version of PICO-8, and must extract the cartridge files under your local PICO-8 carts folder (see README).

In addition, you can download the background of the itch.io page below as "picosonic itch.io page background 4x.gif".

Changelog

Full devlog on itch.io (contains summarized changes)

Full changelog on GitHub (contains detailed changes)

Credits

• Sonic Team - Original games
• danooct1 - 8-bit remixes of Sonic 3 BGMs for famitracker
• Leyn (komehara) - Programming, Sprite/SFX/jingle adaptation, BGM adjustments

Tools

• Game engine: PICO-8 (also used for tilemap and chiptune editing)
• Code editor: Sublime Text
• Pixel art editor: Aseprite
• BGM conversion: ftm2mid by hertzdevil and midi2pico by gamax92

References

• Sonic Physics Guide for physics
• TASVideos Resources for Sonic the Hedgehog for physics
• The Spriters Resource for original sprites

Special thanks

• BoneVolt aka Slow the Snail for their own tech demo of Sonic on PICO-8, “Sonic 2.5” (PICO-8 forum post and SAGE 2020 entry), which motivated me to finish my prototype and enter SAGE myself

Similar games

• Knuckles' Emerald Hunt Mania (SAGE 2020) (itself inspired by MainMemory's Knuckles Emerald Hunt), where you play as Knuckles to collect emeralds directly in the level, using a radar as in Sonic Adventure 2