Hold left upper flipper up and shoot the lane behind it. Repeat. There is a video somewhere of Elwin putting over 1 million doing only this.
Shoot the upper drop targets or the lower-right set when lit to advance bonus multipliers. Bonus is a key element!
Completing 1-5 in sequence lights the Collect Bonus saucer, along with other awards listed on the playfield.
Completing the upper right targets with 3 of a kind will light spinners (blue/yellow) or Special (red).