Global Defense is one of those classic late-80s shooters that feels like it was ripped straight from an arcade cabinet—except it somehow ended up on the Sega Master System. You're basically defending Earth from waves of incoming missiles and UFOs, which sounds simple until you realize how fast things get chaotic. The whole "Strategic Defense Initiative" theme gives it this weird Cold War vibe, like someone at Sega really wanted to make a game about Reagan-era space lasers.

At first, it seems straightforward—just blast everything before it hits your bases—but the patterns get brutal fast. The UFOs zigzag unpredictably, and some missiles split into smaller projectiles mid-flight. I remember thinking the controls were a little stiff at first, but after a few runs, you get used to the rhythm. The music’s got that classic Sega synth sound, too—kinda cheesy but weirdly intense when you’re barely holding off the last wave.

It’s not the deepest shooter out there, but if you like old-school bullet hell with a retro-futuristic twist, this one’s worth a few credits.