MISSION REPLACEMENT: SA1 Gamma-Timer Variant over Kill X Many Missions

By Twilord

This code changes "Kill X Many" missions into ones based around an SA1 Gamma style Timer.

Killing an enemy earns you five seconds, killing an ally costs you ten seconds.


The layout of objects in these levels have been modified to make the challenge easier for the average player:

Stg100 - Westopolis (Hero Only)

Stg201 - Glyphic Canyon

Stg301 - Prison Island

Stg302 - Circus Park

Stg401 - The Doom

Stg404 - Death Ruins

Stg501 - Air Fleet

Stg502 - Iron Jungle

Stg504 - Lost Impact

Stg601 - Black Comet

Changes include:

Partner Spawn Location - to alert players to the Time quickly, without damaging ludo-narrative design.

Enemy Numbers - increasing the number of enemies and decreasing the number of allies, in order to ensure players have an easier time rushing through the levels.

Layout Edits - intended to remove any 'maze like' expects of those stages, as to serve the more urgent mission. This includes removing or editing platforms, and/or remove switches and locking doors that might otherwise enable backtracking. It also serves level flow, and in one case allowed Shadow to mostly complete his open.

Other Mission Criteria - Westopolis (Dark) and The Doom (Hero) have had their mission numbers lowered; the intention of this is to allow them to still be somewhat pleasantly completeable despite the alterations to their levels.


This is NOT intended to be hyper-challenging, but rather to help unlock the mechanical potential of Shadow The Hedgehog's mission system.


dreamsyntax - helped me learn about Gecko Code creation, with specific aid in the creation of this code

TheHatedGravity - helped me get into the modding scene for Shadow


My dear late dog Shadow, who was named in hype for this game all those years ago. I hope this manages to help show the potential I saw in this game back when I did so to a new audience.



1. Acquire/Dump an NTSC-U (USA) version of Shadow The Hedgehog. Add it to Dolphin.

2. Extract and patch the game ROM in Dolphin.

a. Right Click Game, Press Properties. https://i.imgur.com/MMEyHSY.png

b. Navigate to Filesystem tab, right click Disc and press "Extract Entire Disc". https://i.imgur.com/IHLiqsU.png

c. Copy the `files` folder from the submission (https://i.imgur.com/84S2u53.png) to where you extracted the ROM. Click `Replace` when Windows asks if files should be replaced. https://i.imgur.com/zKd92XC.png

3. Add Gecko Code to game.

a. Right Click Game, Press Properties. https://i.imgur.com/MMEyHSY.png

b. Navigate to "Gecko Codes" tab. Click "Add New Code...". https://i.imgur.com/U414OQv.png

c. Give it a name and paste the code from GeckoCodes.txt in the `Code` box. https://i.imgur.com/CsAuyy3.png

4. Run the game.

a. Your new modified copy of Shadow should show in your Dolphin games list; with a file size of 0.

b. If in doubt whether this is the correct game, go to Properties -> Info and check the file path. https://i.imgur.com/pRMlcTj.png

This is a judge note added by Sewer56, because the original instructions assume the user is familiar with unpacking/modifying games in Dolphin; which in practice is unlikely to be the case. All text above the delimiter '=====' is the original author submitted submission text.

  • dreamsyntax helped me learn Gecko/Assembly, with a focus on codes specifically centred around acheiving this

File Type: 7z

File Size: 17.35 MB

Sovic91 @ 2021-10-11 03:35:49

Hey, I remember this one. Congratulations for geting it to SHC.