When you fire up Metroid II on your Game Boy and see the opening animation of three Metroids breeding in desolate caverns, the game sets the tone immediately: you're not here to rescue a princess. You're here to exterminate an invasive species. Red dots on a black background. That's all you need.

This sequel to the original Metroid takes place on planet SR388, where Samus must destroy the Metroid Queen and all her larvae before they spread across the galaxy again. It's essentially a hunt. You forge your own path through the underground—divided into sectors, each with its own atmosphere and hazards—systematically eliminating increasingly tough Metroid variants. There's no linear story here, just exploration with purpose: find every Metroid in each life stage and eliminate them.

Samus has limited abilities on the Game Boy, and that's a genius design decision. No sound, lower graphical fidelity—yet the game delivers the thrills. Jumping between platforms, charging your weapon, exploring passages you couldn't use at first due to missing upgrades, then coming back once you're powered up. The controls are responsive, Samus moves fluidly. Encounters with Metroids aren't brutally hard; they're tense confrontations where you realize what your opponent can do. The game challenges you sometimes, but not out of frustration—more from respect for what's moving across the screen.

Metroid II proved that the Game Boy was more than just Tetris. It showed that 2D exploration and action could run on a handheld without compromise. It foreshadowed the design philosophy that would flow into Super Metroid and define Metroidvania for a decade. Beyond its graphically spartan look—a line-art style, monochrome backgrounds—nothing here feels dated. The mechanics hold up even today.

If you want to play the original, love exploration, and don't mind a limited color palette, the Game Boy version won't disappoint. And if you're after something for older hardware that shows you why Metroid became a classic, Metroid II is the perfect entry point. Today you can access it through emulators or the 3DS remake—both work, but it feels more authentic on that green monochromatic screen.