Game.ObjParticles doesn't have the same radius/scale as displayed in World Editor if YZ is changed but not X itself.
This can be easily tested in Tutorial 22 - Light and Particles and changes the YZ scale, it will be larger in World editor but in-game it will be small because it uses the X scale only.

   

Digging through the code I think the problem is that Game.ObjParticles.create() uses

Because obj.scale() use Matrix.x.length() instead of matrix.scale().avg() or obj.scale3().avg() which seems to be what World Editor is showing (Didn't check the code myself)

I wonder if scale() only used X is intended but would you mind fixing ObjParticles so it won't cause confusion?