Datastorm

The Defender gameplay was the basis for this shoot 'em up, with a horizontally-scrolling landscape which eventually loops back on itself. Your basic task is to pick up each of the 8 pods in turn, and carry them through a portal elsewhere in the level, before going back for another one.

There are power-ups available, representing an auto-fire (Surely one of the earliest software implementations of this), extra simultaneous lasers, missiles to home in on the Landers as they attack, a level-skip, and a Super Shield.

As standard in Defender games, Lander craft are also there to pick up the pods, and these must be stopped before reaching the top of the screen, as both the Lander and Pod become fearsome enemies if they do. If you shoot the Lander, the pod drops back to the ground, for you to retrieve. Unusually, you don't have to wait for the Lander to attack before picking up a pod.

You must shoot all enemies to progress to the next level, at which point you get a bonus for the number of remaining pods. Every four levels the pods are replenished, which means that losing them on the first of each set of 4 levels (1,5,9,13 etc.) reduces your next four bonuses. If you don't save at least one pod on each level, your will have to face tougher enemies, and without your shield being replenished.