Spirebound is a free idle game where you run a wizard’s tower in your browser. You build rooms, research upgrades, send familiars on expeditions, ascend, and summon gods. It is a single HTML file, it needs no account, and it saves to your browser by default. As of October 3, 2026 it is live at spirebound.dhseadev.online, and the Spirebound project page has the details.
What is in Spirebound?
Spirebound merges eight of my earlier game prototypes into one game. I counted from the game itself. It has 6 rooms, 22 research nodes, 6 familiars, 5 zones, 5 gods, 57 achievements and 7 colour themes. The 14 runes are 5 elements, 4 spell shapes and 5 modifiers. Progress while the tab is closed is capped at 2 hours.
Why does Spirebound have its own address?
The optional cloud save keeps a sign-in token in the browser’s storage. Browser storage is shared by every page on the same address, so I did not put a game that holds a token next to the other games. Spirebound has its own subdomain instead. When it is listed in the arcade, the arcade will link out to it rather than embed it.
What leaves your browser?
On a normal load, one network request, for the page itself. I measured that on the live site. Your save stays in your browser unless you choose to sign in for cloud save. The page’s security policy only allows connections to three Google hosts, which are the ones sign-in and saving use, and my local attack tests showed requests to other hosts were blocked. How I built that part is in what I learned putting Firebase sign-in behind an idle game.
What is not finished?
Sign-in works on the live site, which I confirmed myself. A save on one device loaded on another has not been tested yet. I also have not tested audio on an iPad or Safari, used it with a screen reader, or put it through a stranger test. The itch.io page is still waiting on an upload. Two things are weak. Two tabs can overwrite each other’s save. Moving your device clock forward can grant the 2-hour offline bonus early.
If you like this kind of game, the same shelf has Mosslight, Singularity Tower and Spellsurge.