@levrault Particles - overhead and not needed complexity (you dont spawn thousand of objects).
Blender baked animation - one option, but can be "too static" because it repeat only this single animation every time (ofc you can make many and load random).

Just script that spawn meshes at position wiht some init-speed and you can even add "physics layer" to them - and to optimize you can make static amount like 100 and show/hide with reposition instead of making new object every time and deleting.