Why do all physics engines still look so floaty?
I know in older games, the recommendation was to keep gravity low (~6 m/s^2 iirc) to help with simulation stability and make things look better, that might contribute to your idea of things being floaty.
I don't find the examples in the git repo to be especially floaty, but I work with a lot of simulators so I might just be used to it.
* Low gravity
* Slow timestep
* Unrealistic mass ratios of colliding bodies
* Incorrect, or lack of, drag