Game Caliber 50
Author/Vendor Mentrix
Released 1990
Game Type Shoot 'em up
Language English
Gens (0.92)
It's twenty years after the end of the Vietnam War. Your mission, should you decide to accept it, is to venture forth once again on the Ho Chi Minh trail and try to rescue some of the downed American airmen left behind.

Okay, so it's an Ikari Warriors clone. At least it's a good one, and in some ways betters its inspiration.