Tangent

A side scrolling shooter in which you fly a spaceship through futuristic
environments and must destroy a set number of enemies to advance to the next
stage. Your ship can fly into two directions and a radar at the top of the
screen shows the enemies’ position. Carefully adjust your ship’s speed to keep
up with the enemies without crashing into them. Colliding with enemy ships or
getting hit by enemy fire decreases your ship’s energy bar. At the end of each
level, you get the chance to destroy a large mothership for bonus points.
Getting hit by a mothership does not damage your ship, but throws you into the
next stage without bonus. As the game progresses, new enemy formations attack
you, standard enemies become more numerous and faster, while motherships get
bigger and carry more weapons.

Tangent