Please do not spoil this game for everyone else.

Controls:
WASD to move

Arrow Keys to look around

[SPACE] to shoot (when you have a gun)

[R] Heal (when you have the right Alien)

If you are stuck, you can click [BACKSPACE] to return to the main menu. All levels can be completed by running through, the objectives and defeating enemies are not mandatory, but it is more fun.