For the epic boss: at start press x and stay on the top screen, u will colide with him, keep pushing him up with your ship so he will never be able to enter the frame. Keep doing this, firing and pressing 'V' and 'F' when needed and u will be able to kill the final boss and he will never fire one single shot. I just buy the ultra bomb and dark energy from the legendary shop.
@GamerCubed Its not only level up fast. You can buy krowns, upgrade everything, rush constructions, etc... Its ok to have some advantages for whom is willing to support the game, but not this. Token dependent, like the first one.