Keys 

Arrow up or space - Fire 
Arrow down or M - Fire a missile 
P - Pause on/off 
S - Start the game 
Left arrow - Move spaceship to the left 
Right arrow - Move spaceship to the right 
Escape - End the game currently playing 

 
Instructions/rules 

If the attacking spaceships comes all the way down to your 
spaceship you lose two lifes 

1. Bonus lifes every 10000 points 
2. When the ufo passes - try to hit it, when you do you gain 
   1000 points and a new missile 
3. 500 points for completing each level 
4. The attacking spaceships may have one more bullet on the
   screen for each level, the game also moves faster
5. You may have 6 bullets on the screen at any time (and only
   one missile)