Engine Setup

Overview

IKEMEN Go is a modern, open-source fighting game engine written in Go. It's fully backward-compatible with classic MUGEN content while adding modern features like online play, Lua scripting, widescreen support, and the ZSS state format.

Quick Setup Checklist

1. •Download IKEMEN Go from https://github.com/ikemen-go/Ikemen-GO/releases
2. •Extract to project directory
3. •Verify Ikemen_GO.exe (Windows) or equivalent binary exists
4. •Configure data/mugen.cfg for your game
5. •Set up folder structure: chars/, stages/, data/, font/, sound/
6. •Create or edit data/select.def for your roster
7. •Launch engine to verify setup

Project Directory Structure

MyGame/
├── Ikemen_GO.exe              # Engine binary
├── data/
│   ├── mugen.cfg              # Master configuration
│   ├── select.def             # Character/stage roster
│   ├── system.def             # Screenpack (menus, UI)
│   ├── fight.def              # In-match UI (lifebars, timer)
│   ├── common1.cns            # Common state definitions
│   └── common.air             # Common animations
├── chars/                     # Character folders
│   └── charactername/
│       ├── charactername.def  # Character definition
│       ├── charactername.cns  # Constants + states
│       ├── charactername.cmd  # Command inputs
│       ├── charactername.air  # Animations
│       ├── charactername.sff  # Sprites
│       └── charactername.snd  # Sounds
├── stages/                    # Stage folders
│   └── stagename/
│       ├── stagename.def      # Stage definition
│       └── stagename.sff      # Stage sprites
├── font/                      # Font files (.fnt, .def)
├── sound/                     # Music and global sounds
├── external/                  # External Lua modules (IKEMEN Go)
│   └── mods/                  # Lua game mode scripts
└── save/                      # Save data (auto-created)

IKEMEN Go vs Classic MUGEN

mugen.cfg Key Sections

[Options]

• •difficulty (1-8, default 4): AI difficulty
• •life (1-999, default 100): Life percentage
• •time (-1 to 999, default 99): Round time (-1 = infinite)
• •GameWidth / GameHeight: Internal resolution
• •GameSpeed (default 60): Ticks per second (always 60 for standard)
• •team.1vs2life (default 150): Life boost for 1v2

[Rules]

• •default.attack.lifetopowermul (default 0.7): Power gain from dealing damage
• •default.gethit.lifetopowermul (default 0.6): Power gain from taking damage
• •super.targetdefencemul (default 1.5): Defense multiplier during supers

[Config]

• •GameWidth, GameHeight: Window resolution
• •RenderMode: OpenGL rendering options
• •FullScreen: Fullscreen toggle

[Debug]

• •Debug (0/1): Enable debug mode (Ctrl+D in game)
• •AllowDebugMode (1): Allow debug key shortcuts
• •ClsnDraw (0): Draw collision boxes by default

Key Concepts

Ticks and Frames

• •IKEMEN Go runs at 60 ticks per second
• •1 tick = 1 frame of game logic
• •Animation times in .air files are in ticks
• •A move at 3 startup + 4 active + 6 recovery = 13 frames total

State Machine

• •Every character is always in exactly one state
• •States 0-199 are "common states" (idle, walk, jump, etc.)
• •States 200+ are character-specific (attacks, specials)
• •States 5000-5999 are common hit states
• •The engine transitions between states via ChangeState controllers

Coordinate System

• •Origin (0,0) is at the character's feet, center
• •X increases to the right (in character's facing direction)
• •Y increases upward (negative Y = below ground)
• •All positions are relative to character facing direction