Sagaia

Sagaia is one of those insanely hard shoot 'em ups in the same vein as R-Type. It's part of Taito's Darius series. The levels are the planets in our solar system with the first level being the Sun.

Story
From the manual:

''Darius, a planet much like Earth, was victimized by an unprovoked attack. Since Darius was a very peaceful planet, its inhabitants were totally unprepared for the sudden, massive onslaught. Two young pilots - Proco Jr., son of the legendary Gio Proco, and Tiat Young - were performing biological experiments on board their battle-ready Silverhawk peacekeeper vessels, when the attack began. Taken by surprise, and awed by the magnitude of the assault, they followed their instincts and ran.''

''Now, some time later, as they search for a new home, Tiat picks up an unusual signal on the ship's radio. "Listen to this, Proco - some kind of distress call..."''

''Proco takes the headset and strains to listen through the thick interference. "...this is Interplanetary Line 9031, requesting assistance. Attacked by unknown aggressor. Heavy casualties. All vessels destroyed or irreparably damaged. Requesting transport for survivors to nearest Galaxy Depot. I repeat..."''

''Tiat and Proco realize, and acknowledge with a nod, that the people in distress are their own fellow Darians. "Only one thing to do," says Proco.''

''"I'm one step ahead of you," says Tiat. "I've already begun plotting a course for Darius."''

''You are the navigator, and you can choose to make the journey aboard the Silverhawk piloted by either Proco Jr. or Tiat Young, but you'd better make your mind up in a hurry. Time is not on your side! You've got to travel from one end of the Milky Way to the other. What's at stake, you ask? A race of people... an entire civilization. Don't waste another second!''