After seeing the hack week projects, especially the particle one, I decided to create my own particle engine.
The collision detection of particles are handled in Lua just like everything else. It uses ImageHandleAdornments as particles and only sets their CFrame in runtime. So they can change color, be transparent, glow, and have an image on them. But they will not get affected by the lighting of the environment.
In the examples below, there are 6000 particles on the screen at a time:
https://cdn.discordapp.com/attachments/142748177592877056/656268206012497930/Jd0rTQy4VM.mp4
The video below gets to 4300 particles max, it costs a lot for particles to be near (~0.5 studs distance) collision objects which is why it lags more:
And you can try it out yourself:
I’m not planning to release this nor make it open sourced.