Multiplayer Coop Top-Down Action RPG

A Godot 4.6 multiplayer cooperative game supporting both local and online multiplayer with physics-based interactions.

Start with arguments:

--host or --join # instantly hosts or joins a game

--room-debug # shows information above each room what types of puzzles it has, and if player entered the room or not...

--webrtc # this selects webrtc network mode directly. if combined with --join it will try to find room and join that.

Features

Multiplayer Support

• Host or Join: Any player can host a game or join an existing one

• Local Multiplayer: Each machine can have multiple local players (up to 4)

  • First local player uses keyboard controls

  • Additional local players use gamepads

• Online Multiplayer: Players can join from different machines

• Drop-in/Drop-out: Players can join at any time during gameplay

Gameplay Mechanics

• Top-Down Action RPG: Classic top-down perspective with smooth character movement

• Physics-Based Interactions:

  • Lift (Tap Grab): Pick up objects above your head and carry them

  • Push/Pull (Hold Grab): Hold the grab button to push or pull objects

  • Throw: While lifting, tap grab again to throw in movement direction

  • Arc Physics: Thrown objects and players fly in realistic arcs with Z-axis simulation

  • Dynamic Shadows: Shadows scale and fade based on height

  • Box Breaking: Boxes shatter into 4 pieces when hitting players or other boxes

  • Damage System: Players take damage and knockback from thrown boxes

Camera System

• Dynamic camera that follows all local players

• Automatically adjusts zoom based on player spread

• Smooth camera movement for comfortable gameplay

Controls

Player 1 (Keyboard)

• WASD or Arrow Keys: Move

• E (Tap): Lift object above head

• E (Hold): Push/Pull object

• E (While Lifting + Moving): Throw object

• E (While Lifting + Still): Place down object

Player 2+ (Gamepad)

• Left Stick: Move
• A Button (Tap): Lift object above head
• A Button (Hold): Push/Pull object
• A Button (While Lifting + Moving): Throw object
• A Button (While Lifting + Still): Place down object

How to Play

Starting a Game

1. Host a Game:

   • Set the number of local players (1-4)

   • Click "Host Game"

   • Share your IP address with friends who want to join

2. Join a Game:

   • Set the number of local players (1-4)

   • Enter the host's IP address

   • Click "Join Game"

Command-Line Testing (Easy Multiplayer Testing)

You can launch the game with command-line arguments to automatically host or join, making it easy to test multiplayer with multiple instances:

Host Instance:

# Windows
godot.exe --path "C:\dev\godot\multiplayer-coop" -- --host

# Or with custom player count
godot.exe --path "C:\dev\godot\multiplayer-coop" -- --host --players=2

Join Instance:

# Windows
godot.exe --path "C:\dev\godot\multiplayer-coop" -- --join

# Or with custom address and player count
godot.exe --path "C:\dev\godot\multiplayer-coop" -- --join --address=127.0.0.1 --players=2

Quick Test Setup:

1. Open 3 terminals
2. Terminal 1: godot.exe --path "path/to/project" -- --host
3. Terminal 2: godot.exe --path "path/to/project" -- --join
4. Terminal 3: godot.exe --path "path/to/project" -- --join

All instances will automatically start and connect - no clicking required!

Available Arguments:

• --host - Automatically host a game
• --join - Automatically join a game
• --address=IP - Server address to join (default: 127.0.0.1)
• --players=N - Number of local players (default: 1, max: 4)

Gameplay

Lifting Objects:

1. Get close to an object (box)
2. Tap the grab button (E or A)
3. Object appears above your head
4. Move + Tap grab to throw it
5. Stand still + Tap grab to place it down

Pushing/Pulling Objects:

1. Get close to an object
2. Hold the grab button (E or A)
3. Move with WASD/stick to push/pull
4. Release button to let go

Other Interactions:

• Walk into objects to push them naturally
• Grab other players the same way as objects
• Throw players for fun chaos! They fly in arcs just like boxes
• Throw boxes at players to damage and knock them back
• Boxes break into 4 pieces when hitting players or other boxes
• Work together to move heavy objects

Technical Details

Network Architecture

• Uses Godot's built-in ENet multiplayer system
• Server-authoritative architecture for consistency
• Supports up to 8 concurrent connections
• Default port: 7777

Project Structure

multiplayer-coop/
├── scenes/
│   ├── main.tscn              # Entry point
│   ├── main_menu.tscn         # Main menu UI
│   ├── game_world.tscn        # Game arena
│   ├── player.tscn            # Player character
│   └── interactable_object.tscn # Grabbable objects
├── scripts/
│   ├── network_manager.gd     # Network handling (autoload)
│   ├── player_manager.gd      # Player spawning
│   ├── game_world.gd          # Game logic
│   ├── player.gd              # Player controller
│   ├── interactable_object.gd # Object physics
│   └── game_ui.gd             # UI logic
└── project.godot

Key Systems

Network Manager (Autoload)

• Handles hosting and joining games
• Manages player registration and synchronization
• Tracks all connected players and their local player counts

Player Manager

• Spawns players for each peer
• Manages player lifecycle (spawn/despawn)
• Handles local vs remote player distinction

Player Controller

• Input handling for keyboard and multiple gamepads
• Physics-based movement
• Interaction system (grab/throw)
• Network synchronization

Interactable Objects

• RigidBody2D-based physics
• Can be grabbed, pushed, and thrown
• Weight affects throw distance

Development Notes

Adding New Features

New Interactable Objects:

1. Create a scene inheriting from interactable_object.tscn
2. Adjust the sprite, collision shape, and mass
3. Optionally override interaction methods

Custom Player Abilities:

1. Add new input actions in Project Settings
2. Implement ability logic in player.gd
3. Add network synchronization if needed

New Game Modes:

1. Create a new scene inheriting from game_world.tscn
2. Add game mode logic in a new script
3. Update the main menu to select game modes

Testing Multiplayer

Local Testing:

1. Run the game from Godot editor
2. Click "Host Game"
3. Run a second instance from the exported build
4. Enter "127.0.0.1" and click "Join Game"

Network Testing:

1. Host on one machine
2. Find the host's local IP address (ipconfig/ifconfig)
3. Join from another machine on the same network
4. For internet play, configure port forwarding on port 7777

Troubleshooting

Connection Failed:

• Verify the IP address is correct
• Check firewall settings (allow port 7777)
• Ensure both machines are on the same network (for LAN play)

Players Not Spawning:

• Check the console for errors
• Verify the player scene is assigned in PlayerManager
• Ensure NetworkManager is loaded as an autoload

Gamepad Not Working:

• Connect gamepad before starting the game
• Check gamepad is recognized in Godot's input settings
• Verify you have more than 1 local player selected

Objects Not Grabbable:

• Ensure object has can_be_grabbed() method
• Check GrabArea collision layers/masks
• Verify object is within grab range (80 units)

Future Enhancements

• Combat system with health and damage
• Enemy AI
• Level progression and multiple maps
• Character customization
• Inventory system
• Cooperative puzzles
• Voice chat integration
• Dedicated server support

License

This project is open source and available for modification and distribution.

Credits

Built with Godot Engine 4.6