The R-Type II is a side-scrolling 2D shooter where you control the spacecraft R-9C. It's the sequel to the original R-Type, with some changes to the weapons. The wave cannon can now track enemies and there are two new types of weapons: search laser and shotgun laser. For the land units, there's a new anti-ground bomb that can be used.
The game has six levels, each with its own boss in the arcade version and most other versions. However, the Game Boy version only has five levels and doesn't include the new weapons.