Space Invaders Classic
The Matrix has 27 shoot 'em ups on file for the Game Boy Advance, released between 2001–2007. 11 of them support multiplayer. They're ranked below by legacy score, so the games that shaped the genre on the GBA come first, with lesser-known picks further down.
Shoot 'em ups (shmups) put you in a ship facing waves of enemies and bullets. Runs are short and intense, and the goal is to survive, collect power-ups and push your high score.
Typical commitment: quick session (under an hour, or endless arcade fun). Tip: Focus on your ship's small hitbox rather than the flood of bullets, and learn which power-ups suit each stage. Most shmups are designed to be replayed many times.