i agree, just get the invaders to go between 0 & 100(depending on your scale) then worry about getting the camera right after.
A cam position of prehaps 50,50,-200 be a good start and mve it closer 2wards 0 to get everything into play.
A cam position of prehaps 50,50,-200 be a good start and mve it closer 2wards 0 to get everything into play.