Gradius: The Interstellar Assault

The second game from the Gradius series to be on the Game Boy was Gradius: The Interestaller Assault, also called Nemesis II (1992). It was one of the biggest Game Boy carts in existence at the time (2 meg), and was completely different from the rest of the series - most of them used music, enemies, bosses and even levels from previous games in the series, but this one did not.

Gameplay
You control a spaceship with which you use to fly through space and several different types of terrain, blasting at spaceships, aliens, organisms, and armaments. You collect power-up pods that you can use to activate power-ups such as speed, bombs, double-shots, lasers, options, and shields. At the end of the level there is a boss creature that you must defeat to continue on to the next level.