What is this computer game?

I'm trying to find a computer game that I played years and years ago. It was one of those side-scrolling shooters - you know, where you play as a spaceship and your purpose in life is to reach the right side of the level while annihilating all enemies. I remember very little about the game or the plot, other than there was a big ship that you had to enter as your tiny ship and destroy from the inside out. All the text was in Japanese, so I couldn't read it. But what I do remember was the heart of this massive enemy ship... literally, a heart. It was a globby, pulsating red mass that you flew into and blasted aliens from within its cramped artificial veins. After defeating the final boss (some sort of big android thing) the mothership explodes and you win the game... but as the credits scroll, you see the heart, spinning slowly through the dark reaches of space. Does this sound familar to anyone???