Go Galaxians

A classic arcade-inspired Galaxians-style game written in Go using Ebitengine.

This project started with fully code-generated pixel sprites (no external image assets) and now includes a playable gameplay loop.

Implementation details

Project was just to test out the speed of the new GPT‑5.3‑Codex‑Spark. The full first iteration from plan to playable game in 8 steps tok less than 10 minutes in total with agent committing after each step.

Features

• Code-generated sprites for:
  • Player ship and explosions
  • Multiple enemy types
  • Bullets and effects
  • Pixel glyphs for UI text
• Vertical arcade logical resolution (224x256)
• Playable loop with:
  • Title screen
  • Player movement and shooting
  • Enemy formation movement
  • Enemy dive attacks
  • Enemy firing
  • Collision detection and explosions
  • Score and high-score HUD
  • Lives, wave progression, game over, restart
• Animated starfield background
• Wave entry timing for enemy formations
• Per-enemy scoring and extra-life thresholds
• Automated tests for sprite generation and core gameplay behaviors

Controls

• Left Arrow: Move left
• Right Arrow: Move right
• Space: Start game / Shoot / Restart after game over

Requirements

• Go 1.22+ (or compatible modern Go toolchain)
• macOS, Linux, or Windows with graphics support compatible with Ebitengine

Run

go run .

Test

go test ./...

Build

go build ./...

Project Structure

• main.go - App entrypoint and window setup
• internal/game/ - Gameplay state, entities, update loop, rendering, combat, enemies, starfield
• internal/spritegen/ - Code-based sprite generation and tests
• internal/render/ - Sprite registry/types
• internal/scene/ - Shared text rendering helpers using generated glyph sprites

Notes

• Sprites are generated once at startup and reused.
• No external image files are required.
• On macOS you may see Metal deprecation warnings from Ebitengine internals during build/test; these are warnings, not failures.

Roadmap Ideas

• Authentic enemy flight patterns and escort logic
• Attract mode and demo loop
• Sound effects and music
• More accurate arcade scoring/timing
• Persistent high-score storage