Reverse Engineering SimTower

This is the story of building https://towers.world, a ~perfect, tick-for-tick reproduction of 1993 game SimTower.

I spent weeks reverse-engineering the original EXE and writing up a detailed spec of how the simulation actually works under the hood — population flow, elevator AI, the whole star-rating system. The specs are all on GitHub if you want to read them: https://github.com/phulin/tower-together/tree/main/specs

It's also collaborative. Multiple players can connect to the same tower, the simulation keeps running as long as anyone's connected, and build actions sync across clients in real time.

Because I rebuilt the UI, I could add features like shift-click to build grids of rooms - instead of painstakingly clicking to build rows of offices and hotels, shift-click allows a 10-floor grid to be built all at once.

The game runs on Cloudflare Durable Objects, one of my favorite web primitives.

Everything is open source: https://github.com/phulin/tower-together

Reverse Engineering SimTower
phulin.me

Very cool! I used to play this game for a few minutes every morning at a friends place before school. With the clone being open source, would you be open to QoL patches? I don’t have anything specific in mind, just curious how close to the original you want to stay.

Amazing, loved this game when I was younger. I would keep restarting every time I thought of a more effective layout.

I don't think I ever made it to the cathedral though.

Oh my gosh, this really brought me back. Haven't played that game in 30 years. What a great use of AI. Thanks for the trip down memory lane.

Love Yoot Tower! Can we clone it next?