I think I was pushing the limits of what the service could handle with my fluid simulations. They're pretty choppy on first playback, but run smoothly the second time.
I built it to be a reference implementation for "Fluid Simulation for Computer Graphics" (1st Ed.) by Robert Bridson. The book is a cleaned up version of his free course notes. If I had the time, I'd clean up the code a little because the book already has a great explanation of how it works.
These remind me of the ASCII fluid submission [0] at IOCCC 2012 [1] by Yusuke Endoh. The source [2] itself can be used as an input to the program (see video [3]), and he also made a colour version [4].
Block - https://asciinema.org/a/125371
Waterfall - https://asciinema.org/a/125380