Right now, all it is doing is drawing translucent copies of itself, and the further away it gets, the less alpha it has. To clarify:
for(i = 0; i < 5; i += 1) {
draw_sprite_ext(sprite_index,image_index,x+lengthdir_x(5+(i*6),point_direction(x,y,xprevious,yprevious)),y+lengthdir_y(5+(i*6),point_direction(x,y,xprevious,yprevious)),1,1,0,c_white,0.5 - (i*0.1));
}
Anyway, a light blur as in the boomerang would kind of blur into itself? If so, I'll write a script that does that and repost with a new video.
With dust, do you mean dust clouds would kick up behind the boomerang? What if the boomerang weren't on hard ground then? Leaves?