Townscaper is a game by Oskar Stålberg. The demo is available here.
All I did was collect the files required by the webpage. I also added a very simple load/save system to save your creations !
Python is required for this to work because it requires creating a http server with:
python3 -m http.server 8034
Use start.sh to automatically start Townscaper as an in-browser app, this only works with chromium-based browsers (for me it's brave but feel free to edit the script).
There is a template .desktop file if you want to add it to your apps.