Galaga '90, a variation of the Galaga series, was released for the PC-FX in the USA. The gameplay is likely similar to Galaga '88 and the original arcade game. Players would control a spaceship, dodging and shooting waves of descending enemies. The '90 in the title might indicate updated graphics, gameplay elements, or a different set of enemies.  The involvement of Namco or a licensed publisher is probable.

Galaga '90 (USA)

Gaia no Monshou (Japan)