Flukz — open-source shmup community resource open-source GPL Windows / Linux devlog  ·  about
// indie shmup & game-dev resource

shoot-em-up / open-source game project

Build and play great shmups in the open

Flukz started as a GPL shoot-'em-up with a built-in level editor. This site is a community resource covering open-source shmup development, genre history, and practical game-dev guides — for makers and players alike.

Read the devlog → About this project
licenseGPL v2+
genreshoot-em-up
platformsWin / Linux
editorbuilt-in
statuscommunity

// what this site covers

[genre]

Shmup History & Design

From early arcade classics to modern bullet-hell. Pattern design, difficulty curves, and what makes a shoot-em-up satisfying.

[code]

Game Dev Guides

Practical devlog-style articles on game loops, sprite collision, level editors, and shipping an indie project.

[oss]

Open-Source Games

How GPL licensing works in games, how to contribute to open projects, and the toolchain for 2D indie dev.

[play]

Play & Playtesting

Playtesting methods, player feedback loops, and audio design for indie titles with small teams.

// changelog

  • v0.9.2Level editor: undo/redo stack; snap-to-grid toggle
  • v0.9.1Bullet pattern scripting via embedded DSL; 12 new enemy types
  • v0.9.0Linux port; SDL2 backend; OpenGL renderer refactor
  • v0.8.5Collision system rewrite; hitbox visualiser for debug builds
  • v0.8.0First public GPL release; Windows installer; basic level editor

// roadmap

  • done  Core shoot-em-up engine
  • done  Built-in level editor
  • done  GPL release + Linux port
  • wip   Community wiki & devlog
  • todo  Mod packaging & sharing tools
  • todo  Steam/itch.io open-source listing

// devlog — latest posts

  • Open Source · March 15, 2026

    How to Contribute to an Open-Source Game Project

    Contributing code to an open-source game is different from contributing to a library. Art pipelines, asset licensing, and playtesting all come into play. A practical guide to making your first meaningful contribution.

  • Game Dev · March 22, 2026

    Level Editors in Games: Why Built-In Tools Change Everything

    Flukz shipped with a built-in level editor from its first public release. That decision shaped the community around it. A look at why editor-first design matters for small open-source projects and how to build one that people actually use.

  • Shmup Design · March 29, 2026

    Designing Difficulty Curves That Feel Fair

    A game that kills you repeatedly is not automatically hard — it may just be poorly balanced. Difficulty curves should teach, then challenge, then reward. Here is how to design a progression that respects the player.

  • Game Programming · April 5, 2026

    Sprites and Collision Detection: The Shmup Foundation

    Shmup gameplay lives or dies on collision detection. AABB, circle overlap, pixel-perfect — each approach has tradeoffs. A guide to choosing the right method for a 2D shoot-em-up and implementing it without bugs.

  • Game Programming · April 12, 2026

    Building a Simple Game Loop for a 2D Shmup

    Every game runs on a loop: read input, update state, render, repeat. Getting that loop right is more subtle than it looks. Here is a practical breakdown, with code sketches, for a basic shoot-em-up architecture.

  • Open Source · April 19, 2026

    GPL Licensing for Games: What It Means in Practice

    Releasing a game under the GPL is not the same as releasing a library under it. Art assets, music, and engine code create overlapping licensing questions. A plain-language guide to what the GPL actually requires for a game project.

  • Genre History · April 26, 2026

    A Brief History of Shoot-'Em-Ups: From Space Invaders to Touhou

    Shmups have a richer history than their reputation as quarter-munchers suggests. From fixed shooters through scrolling space games to the bullet-hell wave, the genre has been in constant technical and artistic evolution.

  • Shmup Design · May 10, 2026

    Bullet-Hell Patterns Explained: Rings, Fans, and Spirals

    Bullet-hell games are not random chaos. They use a small vocabulary of geometric patterns to create readable, learnable challenges. A breakdown of the most common formations and the design logic behind them.

  • Shmup Design · May 3, 2026

    What Makes a Great Shoot-'Em-Up

    Great shmups share a few non-negotiable qualities: responsive controls, readable bullet patterns, and feedback loops that reward skilled play. Here is what separates the memorable from the merely competent.