Always thought it would be cool to make an RTS or simple city builder game in the browser.
Would you recommend this for hacking around or not?
I think the answer is no, as this is a creative repurposing of css3d as a basis for a general 3d engine. That lets you put web content everywhere, even on the triangles of your teapot. Cool, but extravagant
Whereas THREE.js or webgl is purpose-built for realtime animated 3d scenes.
It’s a wide range from an RTS to a simple city builder. I’d say “no” for the former and “maybe” for the latter. Perhaps try it for a couple of hours and see whether you like it or not.