I Like Turtles

Try BOGO in your browser Pouët.net Demozoo Download (signed, unpacked)

About the download. The build hosted here is a signed, unpacked version of the intro — same content, just without the size-optimizing cruncher that compresses it down to 64 kilobytes. The original packed competition build is available on the Pouët page.

Why two builds? Executable packers like Squishy are a normal part of demoscene 64k production, but their compression patterns overlap with what malware uses, so antivirus engines frequently flag them. Hosting a flagged file here would cause search engines and security indexers to blacklist this site as a malware source — even though the binary is clean. The unpacked, signed build avoids that entirely.

About

I Like Turtles is my Revision 2026 entry in the PC 64k intro competition. It didn't place — but it's the production I'm most personally attached to in a long time, because it's a return to the language that first made me want to make pictures with a computer.

Before I knew what a demoscene was, there was Logo. A blinking cursor, a turtle, a couple of verbs, and the small thrill of telling a triangle where to walk. I Like Turtles is that thrill at 64 kilobytes.

The entire intro is rendered by a Logo dialect of my own, which I call BOGO. Everything you see is BOGO source executing in real time: every line, every fill, every camera move. No baked geometry, no precomputed paths — just turtles, all the way down.

BOGO — a Logo for the realtime era

BOGO is a small Logo variant I built for live, synchronized turtle graphics. It keeps the things I loved about Logo — fd, rt, repeat, recursive procedures, the turtle as the unit of intent — and adds the things you need to choreograph a four-minute audiovisual production:

Realtime sync primitives. Turtle motion is timed against the soundtrack rather than emitted as a one-shot script. Beats, bars and arbitrary timelines are first-class.
Hot-reloading source. Edit a procedure, the running scene picks it up on the next frame. The demo was authored this way, and so is everything I do in BOGO now.
Many turtles. Spawning, herding and culling thousands of turtles is the core idiom — closer to a particle system you can talk to than a single drafting pen.
Expressive over efficient. BOGO was designed to feel like sketching, not like writing a shader. Whenever there was a choice, I picked the version that read more like a sentence.

You can poke at the language yourself in the editor here on the site:

to spiral :n :step
  repeat :n [
    fd :step
    rt 11
    spiral :n - 1 :step + 0.5
  ]
end

spiral 200 1

Open the BOGO editor →

Technical Details

Engine

BOGO — a custom Logo dialect with realtime sync, hot reload and many-turtle semantics. The intro is a BOGO program, not a frozen render.

Graphics

Pure turtle graphics, drawn live every frame. Strokes, fills and camera are all expressed in BOGO; there is no precomputed geometry in the payload.

Music

Original soundtrack by andr00, composed to be sync-friendly so BOGO can hang scene events directly off the timeline.

Size

Fits inside 65,536 bytes — interpreter, BOGO source, music and assets included. Packed with the Squishy cruncher.

Competition

Shown in the PC 64k intro competition at Revision 2026, the world's largest demoparty.

Credits

Code, graphics and music by andr00.