Final Boss trick:
The final battle with the overlord can be very difficult. However,
there is one trick to beating him. Equip a gun type that can shot at
a down-left angle. Then simply fly right in front of his forehead,
the only place none of his attacks can reach.Psyme endings:
In the final battle with psyme she is in a battle worm and you have
to fight her. If you only shoot out the three cannons on top she remains
alive to the end. But if you shoot out the eyes on the bottom of the screen
she dies, and is out of the last cut scene.
Unlock Sigma Ship:
Defeat the game once to unlock the Sigma Ship in random encounters.