Orbital is 2048 in space. I built it together with Antti in 2014 and the code is available on GitHub on GitHub. Antti made this demo gif that explains the whole concept, so no need for words:
As was my habit at the time, I started off by writing everything from scratch in vanilla JS + HTML5 Canvas. I reached out to Antti about some issues I had with my homemade physics engine and he solved all those issues by porting to Box2D then improved the codebase and gameplay a lot until it actually became clean and fun respectively. This might have been one of the first times I used bundlers (at the time, browserify was the hot new thing) and started loosening up on my purist tendencies!