← The Crimson Tower

About The Crimson Tower

The Crimson Tower is a minimalist roguelike climb. You draw a sword from the floor of an empty chapel, choose one direction at a time, and survive what the tower remembers about how you got there. Butters lunge, bubbles shoot, colorful terrain rains in with every floor, and on floor sixteen something large is bouncing. Press 3 for red/cyan anaglyph depth if you have the glasses.

Where it came from

The tower was originally built over six months in early 2024 for oncyber, a metaverse platform — and it was nearly finished when the platform's runtime went away beneath it. It sat unplayable for two years, surviving one failed revival attempt, before being rebuilt from its recovered pieces in about a week in 2026 — this time on ground nobody can take away. The rebuild was a genuine human–AI collaboration: Gary (design, direction, the 2024 world and all its recovered assets) and Claude (implementation), working in Claude Code. The full story is on Gary's blog: Anaglyph and the Crimson Tower.

The tower also connects backward: at the very top, past the boss, there is a door. It leads to REACT, an art world Gary built in 2023 with some of the same pieces — the worlds were always meant to tie together, and now one thread does.

Credits

Free, no accounts, no ads. The tower runs entirely in your browser. WASD + mouse · Space jumps · Q dodges · hold right-click to throw the sword.