Hola, tambien puedes dar un buen efecto de sombra asi:
[gml]
draw_sprite_ext(sprite_index,image_index,x,y,1,0.33,0,c_black,0.33);
draw_sprite(sprite_index,image_index,x,y);
[/gml]
Saludos.
[gml]
draw_sprite_ext(sprite_index,image_index,x,y,1,0.33,0,c_black,0.33);
draw_sprite(sprite_index,image_index,x,y);
[/gml]
Saludos.