If Missile Defense 3D wasn’t enough, here we have another Sega cartridge that capitalizes on the Cold War fears that America was still feeling in the 1980s. At one point the country worried about ICBMs attacks from certain enemies so much the U.S. government actually considered making and putting special defense satellites in space to shoot down said missiles, even dubbing the project “Star Wars”. Such a thing never advanced past the planning stages, but that’s why we have videogames. In 1987 Sega crafted an arcade game based on this idea called SDI (or Strategic Defense Initiative), which can best be described as the Atari classic Missile Command melded with a traditional side-scrolling space shooter, and later brought out this Master System port, known outside Japan as Global Defense. This game naturally depicts Earth being attacked, not from within by one of its enemy nations, but by some unknown force from space, and you control a defense satellite that’s somehow the only hope Earth has.
Each stage has two parts, and offensive half and a defensive half. The offensive half finds you orbiting around the Earth scrolling from one end of the area to the other as missiles, aliens and other threats whiz onto the screen. Obviously you need to shoot them down, but your shots can’t blast your targets directly; the energy burst resulting from your bullets’ detonations is what destroys an enemy. The thing is, the original arcade game had an unusual control scheme where you moved the satellite with a joystick that had a fire button on top of it, while maneuvering the crosshairs with a trakball. Unfortunately the SMS cart is stuck with the regular controller and uses Button 2 to fire while you have to hold Button 1 down while using the d-pad to reposition the satellite. Your satellite can only take one hit before dying, but some rare power-ups appear to help you out, such as increasing your blast radius or speeding you up. You also have to beware of letting too many projectiles pass by you; the meter shown at the bottom of the screen represents the damage to the planet itself and it increases for every target you miss. If the meter completely fills up the planet “explodes” (or rather just flashes) and you get an immediate game over.
If you survive the first half, your space shuttle will pick you up and deliver you to the single-screen defensive half. Here you’re in a stationary spot with the missiles you missed in the first half raining down toward you and the planet, and you need to finish them off. Trouble is any damage from the offensive phase carries over to this screen, giving you even less margin for error. Should you outlast the salvo with the planet still intact, its on to another two halves that seemingly takes place on the other side of the planet, with a fresh damage meter to boot. Then you move on to the moon, an asteroid belt and Saturn before finishing up on an alien planet, resulting in around 20 total levels.
The game is decent enough, certainly different from other shooters. The graphics are decent with some okay sprites and nice illustrations for the planets, but nothing terribly impressive. The audio, on the other hand, is rather annoying with a background theme that sounds too bobby fir this setting, as well as the bleeps and bloops for sound effects, some of which can grate on your ears. However what really brings this game down is its awkward control setup which is frustrating to deal which, especially since you have to shift your focus moving and firing at a very high rate. The Missile Command method of eliminating targets may have worked on a single-screen game, but being forced to rely on it in a side-scrolling title doesn’t work very well. Plus the crosshairs are sluggish and will cause you to barely miss out on blasting some targets which only adds to the frustration. It almost makes you wish Sega had incorporated the Sports Pad into this title. The game difficulty is also on the high side and goes even higher, to the point that the later stages are virtually impossible to get through, meaning very few if anyone will ever see the ending without massive amounts of cheating.
So Global Defense isn’t a terrible game, it’s certainly a unique title among the SMS library and might be worth a look, but whether any enjoyment is worth the annoying controls and hair-pulling difficulty is up to you. A better control scheme and more balanced difficulty would have made this cart more fun, but ultimately it’s another forgettable release for the SMS.