Alternate ending
At the end of the game instead of destroying Pysmes ship disable it by taking out the guns instead of the eyes She will fall down to Earth After you kill the Overlord you will find her on Earth When you get back to Earth instead of you being the last man on Earth you will find Pysme down there She will ask you to show her around Earth
Defeating the final Boss
At the start of the game when you manage to get to the final Boss stay at the top of the screen and to the center Switch to your bombs Stay still and keep using them The bombs will drop onto the Boss ship and blow off the pieces If done correctly you should get through the fight without being hit once
New Game
To unlock New Game beat the game and wait through the credits At the end the game will prompt you to save Do so and the next time you start the game the completed save file will have a gun data icon by it New Game allows you to replay the game with all of your old gun data and gives you access to several new endings
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
Scarlets Endings
Whether Scarlet appears in the ending or not depends if you pick up the Virus while on earth the second time or not You can find it in the room above the one where Zart and Tierney were working You cannot return here after you have left so decide what ending you want here
Only available in New Game