Particles
All the other guidelines apply to particles as well, with a few differences.
A collection of particles As seen above, the particles need to be even more cartoonish, simple and recognizable, since they are not only small overall, but also move and rotate in space a lot. They also must be in PNG format, 64x64 and named in PascalCase.
An example of the leaf particles in movement. Players can recognize the shape and color fast enough that the particles do not stay in the world for long. 
