Cycoid is a horizontal shooter, with the ability to aim in 360 degrees with the mouse. It also has some really neat music.
Note: It gets easy if you keep the fully powered-up gun, but try killing yourself (you have unlimited continues) at the beginning of each level for a real challenge.

At the beginning of the game you may select, using the mouse, either BEGINNER or NORMAL mode. Each of these two difficulties has a separate high score. On each level you have three to six lives (depending on the difficulty). At the beginning of each level these are replenished, regardless of how many remained at the end of the previous stage. If you collide with an enemy bullet or ship you will lose a life and immediately reappear in the center of the screen with brief invulnerability.
If you run out of lives, the current stage will restart, and you will lose your score and weapons.

Collect the flashing and sparkling powerups to gain new weapons. There are four weapons in total, which accumulate on your ship. If you have all four weapons, your missiles will become highly powered-up.
The color of the powerup when it is collected determines which weapon is enabled.
Your current weapons are displayed in the top-left of the screen.

BLUE: Your main shot gains a satellite bullet.
RED: Two missiles that seek the targetting reticule.
GREEN: A horizontal wave will compliment main fire.
YELLOW: Main shot and horizontal wave will fire 50% faster.

Controls:

Fly with W,A,S,D or the arrow keys.
Aim with the mouse.
Hold left-click to fire your weapons, and hold right-click as well to fire horizontally regardless of the position of the targeting reticule

No install needed