Tomcat

In the first half of 21st century technological advances allowed for
construction of artificial islands. One of such military installations,
ARTROCK 6, had turned rogue after being hit by a violent storm, its computer-
controlled defensive systems firing upon anything that comes close. The
player, being a top pilot, has been chosen to fly an upgraded F-14+2d Tomcat
jet to destroy this electronic madness.

Tomcat is a vertically scrolling top-down shooter set in the near future.
You can pick up weapon upgrades (more guns, missiles) from destroyed enemies.