Red Zone was a top-down shooter developed by Zyrinx, distributed by Time Warner and released for the Sega Genesis in 1994. Zyrinx itself makes for an interesting story. It was a development studio originally formed from two Amiga demo groups in Europe that relocated to Boston. They developed two games for the Genesis including this one and Subterrania which was released the previous year.
The plot of Red Zone centers around a guy who steals some nuclear weapons from the USSR and is threatening to destroy the world. Your job, of course, is to stop him. During most of the game you will be flying a helicopter armed mostly with cannons and missiles. However, you will be on foot for some parts of the game.
Red Zone has gotten pretty mixed reviews over the years. Early on, magazines gave it pretty mediocre reviews, citing the difficulty and poor control of the ground segments. More recent reviews are much more positive overall. The game features some pretty brilliant graphics and effects for the Genesis including rotation, real-time zoom, and full motion video compression among others. The helicopter sequences are excellent but the ground sequences take some getting used to. At the end of the day, if you want a VERY challenging top-down 16-bit shooter that was state of the art at the time and impressive even today, then you'll have a hard time doing better than Red Zone.
Red Zone does not have any sequels or re-releases on modern platforms and it was only ever released for the Genesis. However, the original beta version of the game, called Hardwired, was made freely available by the developer. I'm not really sure what the differences are between this beta version and the final version. Loose carts of Red Zone can be found for not too terribly high prices and both Red Zone and Hardwired can be found easily enough if you want to play on an emulator.
The above ad is from the February 1995 issue of Electronic Gaming Monthly.