Protector

Protector is a horizontal side-view scrolling shooter where the screen
scrolls constantly left or right as you control a ship trying to stop an alien
invasion force. You were just flying a few solons above your home planet when
you were attacked and it is your job to destroy as many of the invasion force
as you can to save your planet. As you fly left or right, the aliens appear
and you keep blasting them avoiding the aliens and their bullets. if you touch
an alien or it’s bullets then you lose one of three lives. Before you start
the game you can select the skill level (1-9).

Protector