Core Design's Frenetic is probably the most intense vertical scrolling game I've ever seen! You're in a ship, flying up into combat. Each level has a series of enemies culminating in a fight with a boss. There are 8 levels of varying complexity and methods to overcome your adversaries. You begin with 5 lives, but you'll probably need a lot more. Fortunately, this version has welcome screen where you can enable unlimited lives! After you beat the level's boss you are sent to the next level. There are several strategies but having quick reflexes is the most important one.
For complete instructions and a walkthrough
watch the video below