Sinistar is an arcade game released by Williams in 1982. It belongs to a class of video games from the 1980s called "twitch games". Other "twitch games" include Tempest, Defender, and Robotron: 2084.
The player pilots a lone fighter ship through a quadrant of the galaxy, initially blasting away at drifting planetoids to "mine" Sinisite Crystals from them, which, when harvested, create Sinibombs. Sinibombs are the only weapon capable of damaging Sinistar. The fighter's bomb bay can hold 20 Sinibombs.
At the same time that the player is trying to get crystals, the "worker" ships are also trying to take the crystals. They use these crystals to create Sinistar, the skeletal-looking Boss who is trying to destroy you. At the same time that all of this is going on, other ships (called "warrior ships") are trying to shoot the player's ship, and also shooting at planetoids to mine crystals.
The worker bots must harvest 20 crystals to complete Sinistar. Once it is completely formed, a digitized voice says: "Beware - I live!". While Sinistar is trying to collide with the player's ship in order to eat it, he has seven more sayings: "Beware, I live!", "I am Sinistar!", "Run! Run! Run!", "Beware, coward!", "I hunger!", "Run, coward!" and "RAAAAAAAHR!!!" If the Sinistar succeeds in colliding with the player's ship, the ship spins out of control and Sinistar eats it, causing the ship to explode.
How about a excellent emulation of this classic game, done with Shockwave?
My only complaint is that you can't change the size, so everything is really tiny. Makes me want to set my desktop resolution back to 640x480.
See also, The Philosophical Revelations of Sinistar.