Dropzone is a shoot 'em up video game developed by Arena Graphics in 1984. It is a bi-directional, horizontally scrolling shoot 'em up in the style of Defender. It was designed and written by Archer MacLean, his first commercial video game. In fact, "Arena Graphics" is just a shell name for MacLean himself. It was released for the Atari 400/800 and Commodore 64, then later ported to the Nintendo Entertainment System, Game Boy, Game Gear and Game Boy Color.
Dropzone borrows many elements from the Defender, including the same font style, alien depictions and title screen depictions.
The gameplay is much in the style of Defender, as well as Stargate, Scramble and even Robotron: 2084. Players control the hero trying to rescue the scientists on a horizontally side-scrolling game field. Players must elude or engage various aliens-some slow, others faster-and return the scientists to the base's eponymous dropzone. The aliens capture scientists walking along the ground. The player must shoot the enemy aliens and catch the falling scientists. Sometimes the aliens will carry lethal androids instead, which must be avoided.
Source: Wikipedia, "Dropzone", available under the CC-BY-SA License.