 *Turrican* on the Game Boy is a run-and-gun shooter, likely borrowing elements from its console counterparts. The gameplay would involve navigating levels, shooting enemies, and collecting power-ups.  The Game Boy version would probably adapt the gameplay for the handheld's limitations, perhaps using simplified graphics and controls compared to the original.   More information is needed to know about the developer or publisher.

Turrican (USA, Europe)

Turn and Burn (USA)