Doink!

A local two-player arcade football game for mobile, built with the Corona SDK (now Solar2D) in Lua.

Two players share one device in portrait orientation, sitting at opposite ends of the screen. Each defends the goal on their side. First to five goals wins.

The in-game guide still describes a match timer instead; no timer was ever implemented.

Gameplay

Your player is not moved freely — it slides continuously along the border of its own half of the pitch. You control it with two buttons:

• Red button — shoots your player into the field to hit the ball.
• Green button — inverts its direction along the border, so you can line up the angle before firing.

Once shot, the player travels across the pitch and is re-hooked to the border on completion.

Power-ups

Each player has two power-up slots shown at mid-field on their own side: the one currently active and the one coming next, so you can plan a couple of moves ahead. They are drawn at random from five types:

Power-up	Effect
❄️ Snowflake	Freezes the ball if it is moving.
👊 Fist	Launches your player much faster, for a more powerful shot.
🧱 Wall	Raises a barrier in front of your goal. If used while detached from the border after a shot, the wall is built at the player's current position instead.
🌀 Teleport	Sends your player back to its own goal line and re-hooks it to the border. Only usable after the player has been shot.
🚫 No entry	Does nothing — a null power-up, there to keep matches unpredictable.

Modes and settings

Both modes run inside gameView.lua, switched by global.gameMode:

• Match (gameMode = 1) — the two-player game described above, with a pause overlay and an end-of-match popup.
• Training (gameMode = 2) — solo practice. Note that the ball is not involved: in training it is created with no physics body and hidden, and player 2 is hidden and stationary. The targets carry the ball's collision filter, whose mask includes the players, so you shoot yourself at them. Three targets spawn, each answering with a cheer; clearing all three returns to the menu. The staging is scaffolded (trainingStage) but only one wave is implemented.
• Settings (creditsView.lua) — music and SFX toggles. The difficulty selector is commented out and global.difficulty is not read anywhere, so difficulty currently has no effect. Settings apply immediately but are not persisted.
• Customization — selectable ball and pitch skins (ballView.lua, fieldView.lua), with assets in balls/ and fields/. The pitch choice also drives the UI theme: power-up icons and the menu, restart and back buttons come in neon, black and white variants selected from global.fieldType.

An in-game guide with the full rules is in guideView.lua (text in Italian).

Technical notes

• Engine: Corona SDK / Solar2D, Lua.
• Scenes: managed with the composer module; UI built with the widget library.
• Physics: Box2D via Corona's physics, run with zero gravity (physics.setGravity(0,0)) — it is a top-down pitch, not a side view.
• Collision handling: the pitch, nets, players and ball each get their own category/mask bits. Several alternate filter sets exist in gameView.lua so that power-ups (the wall in particular) can re-body objects and change what collides with what mid-match.
• Curved borders: players follow the rounded pitch outline through an ellipse equation (EllipseY) plus timed transition.to segments, rather than physics-driven movement.
• Content area: 320×480, letterbox scaling, 60 fps, portrait only.
• Input: multitouch, so both players can press their buttons at the same time.
• Persistence: none. Settings live in a shared table in memory and do not survive a restart.
• Audio: music is streamed with audio.loadStream; effects are short MP3s gated on the SFX switch.

Project layout

main.lua                  entry point — activates multitouch, loads the menu
config.lua                content area, scaling, fps
build.settings            orientation, permissions, icons, per-platform excludes
Icon*.png                 app icons (must stay at the root — build.settings
LaunchScreen.storyboardc  and the iOS bundle reference them by bare filename)

scenes/
  menuView.lua            main menu
  gameView.lua            match and training: pitch, physics, players,
                          power-ups, scoring, pause and end-of-match popup
  guideView.lua           scrollable how-to-play text
  creditsView.lua         settings and credits
  ballView.lua            ball selection, page 1 (ballView2.lua is page 2)
  fieldView.lua           pitch selection

lib/
  variables.lua           shared global table passed between scenes

assets/
  balls/ fields/ goal/ powerups/   gameplay art (power-ups in B/N/W themes)
  buttons/ widgets/ images/        UI art and backgrounds
  training/                        training-mode targets
  sounds/                          music and sound effects, all MP3

docs/
  Doink!.pdf              design document
  DEBUG_INVERT.rtf        debugging notes from development

Scenes are loaded by module path (composer.gotoScene("scenes.menuView")). Asset paths in code are resolved from the project root, not relative to the calling file.

Building

The project has no build script — it is opened directly by the simulator:

1. Install Solar2D (the free successor to Corona SDK; the project predates the rename and still references docs.coronalabs.com).
2. Open the Solar2D Simulator and point it at this directory (the one containing main.lua).
3. To produce an installable build, use File → Build for Android or iOS.

The Android build only requests android.permission.INTERNET. iOS uses LaunchScreen.storyboardc and the bundled Icon-*.png set.

Prebuilt APKs are not tracked in this repository (*.apk is in .gitignore).

Credits

Made by Alessandro Chiabrera, Matteo Ferrini, Luca Montenero, Riccardo Rocco.

The design document is included as docs/Doink!.pdf.

License

The source code is released under the MIT License.

This does not extend to every file in the repository. The provenance of the sound files in sounds/ has not been verified, so check those separately if you reuse the project.

Two third-party items that used to carry their own terms — a Blade Runner fan font and the GGData save helper — were unused and have been removed.

Status

Started in 2017, with a substantial round of work in 2021 that added training mode, the themed UI, the pause overlay and the five-goal win condition. That build shipped with training disabled behind a "coming soon" label; it was finished and switched on in v6.1.0.