Gaplus is a shooter from Namco
This Game is a sequel to Galaga and has similar gameplay. However, it has a much deeper gameplay in later levels.
The player controls a spaceship, that can now move vertically (limited to halfway up the screen) as well as horizontally, and shoots at swarms of incoming insect-like aliens which fly in formation above it and swoop down to bomb it in a kamikaze-like dive. In this sequel, the level starts over if the player is killed before all the enemies have come in. When all enemies are destroyed, the player moves on to the next level. By obtaining certain power-ups, it is possible to shoot 60 bullets per screen, the most any Galaga related game has.