X (Japan) was one of those Game Boy games that made you go, "Wait, how is this even possible?" It pulled off full 3D polygons on Nintendo's little gray brick—something nobody expected back in the day. The graphics are blocky as hell by today's standards, but at the time, it felt like holding a tiny arcade machine in your hands.

You pilot this angular spaceship through wireframe tunnels, dodging obstacles and shooting down enemies. The controls take some getting used to—everything moves at this weird, floaty pace—but once it clicks, there's something hypnotic about weaving through those jagged neon corridors. It's short, rough around the edges, and definitely not for everyone, but as a tech demo for what the Game Boy could do? Wild stuff.