IMO normal maps work well when you want to add some detail for example to player charaters like facial features, and when you want to add some bumpiness/detail to terrains (like rock type of surfaces) & weapons. Flattish, metallic surfaces like "spacestation walls & floors" look easily too flat. Normal maps have their limitations and their advantages, but since Blitz does not support them properly it's waste of time to even think them. And like said here, you can do very nice looking game without them.