Tons of customization be done through our Mapmaker Tool! Use one of our templates, draw your own custom layout, and fill your maps with special effects and all kinds of objects from our huge library of pixel art.
For extreme power users, all the art we use to make our maps is open source here:
GitHub - gathertown/mapmaking: Maps, tilesets, and assets oh my!
Feel free to go wild with it! We recommend Tiled, a great free tool for custom large-scale pixel art.
For automation and programmable behavior, check out our (beta) Gather HTTP API! It can only do a few core things right now, but coming very soon is a much more powerful realtime websocket API which will allow arbitrary 3rd party logic to totally customize in-world behavior—join the developer mailing list to get an email when it's released!