Blue Thunder is a side-scrolling shooter and tie-in with the short-lived TV series of the same name which has you piloting a new 'jetcopter' as the only survivor of an alien assault. As it turns out, you're not alone after all, so you depart from your ship and fly across a sea full of heavily defended islands to reach the enemy stronghold, disable its defenses and rescue your comrades.
Should you succeed, you get to try it again at a higher difficulty level, where you'll face enemies with higher firing rates, planes, barrage balloons and missile-armed submarines. All the while you'll have to keep an eye on your dwindling fuel supply. Your jetcopter can fire at any angle it's flying, even straight down.
The C64 version scrolls in the opposed direction and has a few smaller differences in the environmental graphics. The Atari 8-Bit version was later re-released with a new TV show license (Airwolf) and a new helicopter model.