Sandcastle Builder

Sandcastle Builder is Eternal Density's 2013 idle based on xkcd #1190, Time, the 3,099-panel sandcastle comic that won a Hugo Award: click the ONGer frame to dig sand, cast castles, tool up, earn badges, blow glass, raise monuments, and even travel through the story's own time loops. It is the deepest fan-idle ever built on a comic strip, Cookie Clicker-inspired but carrying a decade of continuity jokes that only Time's readers fully decode.

What the loop feels like

You dig a sandcastle, the sandcastle casts a tool, and the tool digs for the castles you will build after the time alignment is right. That's Sandcastle Builder.

The comic's structure is the game's clock. Time published one panel every half hour for months, and the game honors that rhythm with NewPix, its own unit of frame-time, so progression literally happens at the comic's pace and the joke is that idle players, of all people, are waiting for scheduled content. Tools dig for you, badges track absurd milestones, monuments rise, and the sandcastle physics of the original strip become an economy. That's Sandcastle Builder: an idle game about a comic that was itself about waiting.

How it actually works

The documented systems span the genre's full deck: active clicking on the ONGer frame, idle progression through tools and castles, automation as the tools multiply, and prestige through the time-travel layers the comic's plot demanded. The community around it, the xkcd Time fandom wiki and the game's own subreddit, documented a machine dense enough that exploring it is part of the fandom experience, with references landing on schedule as the comic's saga unfolded. Preservation is the entry's other achievement: the original host, castle.chirpingmustard.com, is dead and the domain was taken over by a squatter, per the Time wiki's own record, so the live mirror at crashsnowdon.com is the canonical way in, verified serving the real game HTML. The source is open on GitHub, the wiki and community survive, and the entry notes the art license honestly: CC BY-NC, non-commercial, recorded in the sidecars.

The fandom context is what elevates it. Time was a community event as much as a comic: readers lived in the discussion threads, mapped the story's physics, built sandcastle physics of their own, and the game turned that collective annotation into mechanics. Badges reference community memes, the Magnus arg, the Beanies, the time-loop structures the readers charted panel by panel, and the game's own changelog followed the comic's plot in near-real-time. As a piece of collaborative fan craftsmanship it is nearly unique: open-sourced, community-documented, mirrored by fans when the original host died, and still maintained by its audience a decade on. The catalog's defunct-adjacent shelf is full of games the internet forgot; this is the rare one the internet actively decided to keep alive.

Playing it today

Free at the live mirror, open source for the curious, with the fandom wiki as the manual the game never ships. Read xkcd #1190 first or last; the game works either way, but the NewPix jokes land better with the comic behind you. For the genre's other monument-builders, Cookie Clicker is the acknowledged inspiration.

The verdict

The deepest fan-idle ever built on a comic strip: a Hugo-winning source, a decade of continuity jokes, and tools that dig for you while you wait for the next NewPix. A fandom milestone you can play.