pixelfx

pixelfx is a free MIT library of 244 pixel art game effects drawn by code, with sprite sheet export and a Claude Code skill for making new ones.

What it is: effects as small programs, not image files

The repo is by Patch (patch.gg) and is MIT licensed, for code and effects, commercial use included. Each effect is one JavaScript file in src/fx/<category>/ that draws pixels at run time. Because there are no images, you can play an effect live, recolor it, mirror it, reseed it or render it to a sprite sheet.

• The README lists 244 effects in 21 categories, from fire, explosions, ice, lightning and weather to impacts, status effects, UI, pickups and screen transitions.
• Each effect draws into two buffers: a color buffer for pixels, which can be opaque, dithered or translucent, and a light buffer for additive glow. The README says that is why hot things look hot.
• Every random number comes from the effect's seed, so frame 40 is the same every time. Simulated effects step particles at 120 Hz, so sparks and smoke behave the same at any frame rate.
• Any effect takes a palette, a dark-to-bright list of hex colors, so a fire can burn blue or a heal glow pink without touching its code.

Characters that act the hit out

The README says an effect alone looks like a sticker, so 61 of them come with a character that winds up, lets go, freezes on contact and recovers, while a straw target takes the hit. Twelve "moves" chain effects into whole attacks, such as an arrow shot, a dash strike, an earth stomp, a fireball throw and a holy smite. The stock character is a grey 24 by 38 pixel dummy built on a 3D skeleton and drawn down to pixels, which the README compares to how Dead Cells makes its sprites.

• The timing is plain data in act on each effect, or under meta.pixelfx.act in a sprite sheet's JSON, with wind-up, recovery and the freeze time at each hit. If you have your own character, you can start your wind-up that long before the effect and pause everything for the freeze.
• Effects drawn on the body, such as frost or poison, are written against the standing dummy. The README says to regenerate those if you ship them.

Using it in a game

• Browser games: install with npm i github:patch-gg/pixelfx, or copy src/core and the effects you want. The README names canvas, Phaser, PixiJS, Kaplay and three.js, and says there are no dependencies.
• Other engines:node tools/render.mjs ice/frost-nova --sheet writes a transparent PNG of every frame and an Aseprite-style JSON with frame rects, durations, fps, loop, columns and the pivot. The README says Phaser's atlas loader and the Aseprite importers for Godot and Unity read it, and names GameMaker, Defold, LÖVE and Bevy as other targets. node tools/sheets.mjs exports the whole library.
• Previews:--gif and --mp4 show the motion, and node tools/serve.mjs runs the gallery locally with your own effects in it. The tools need only Node.

The Claude Code skill

The pixelfx skill teaches Claude Code to find, use, export and make effects. In Claude Code, run /plugin marketplace add patch-gg/pixelfx then /plugin install pixelfx@pixelfx, or copy skills/pixelfx into ~/.claude/skills/.

• The README's example requests include adding a frost nova to a mage's ultimate, making five takes on a coin pickup sparkle, exporting the fire and explosions categories as sprite sheets for Godot, making a floaty hit feel punchier and giving a spell a wind-up with a reaction.
• To make your own, node tools/new.mjs arcane/my-spell creates a starting file, render.mjs writes a contact sheet to look at, and check.mjs flags problems such as seams, unseeded randomness and slow frames. The loop is draft, render, look, fix, render again. docs/AUTHORING.md holds the drawing API and the quality bar.

Where the method comes from, and what is not covered

• The method is Hugo Duprez's, from his Sprite Fusion post on making pixel art effects with Claude: code is clay, trust your eyes, feed your references. The README says src/core/sim.js and the effects that say so at the top adapt his MIT code, and that parts also come from Hollow Crown's MIT source. The frame shape matches Sprite Fusion's VFX, so the two libraries can draw into one frame.
• The Patch Pixel font in gallery/fonts is Patch's own and is not under the MIT license. See NOTICE.md in the repo.
• It makes code-drawn pixel effects only. It is not a sprite editor, and it does not draw characters other than the stock dummy.

How fresh it is

• The repository was created on October 30, 2026, and its last push was on October 31. On November 7 it had about 5,700 stars, 748 forks and 10 open issues.
• The name is shared with an unrelated site, pixelfx.app, which is an AI headshot and background editor. It has nothing to do with this repo.
• Seailife did not install it, run the tools or open the gallery effects in an engine. The effect count and platform notes above are from the README.