A first-party Nintendo shmup for the Game Boy basically exists just to show that you can do this kind of game for the platform.

Solar Striker is exceedingly simple. It's a vertical shmup with one power up that gives you double, then triple, then double (but stronger?) shot.

Levels often repeat obstacles, and it's fairly easy, but it does have quite a few mini-bosses and bosses, which surprised me.

An interesting page in Game Boy history, worth playing nowadays only if you want something almost Galaga-simple.