A spaceship top down shooter.
Cheats
5 Bombs
On the title screen, select "New Game" whenever the background animation is flashing white. If you get the timing right, you'll start with 5 bombs instead of 3!
Hidden 1UP
In stage 3, just before you reach the open harbour, you'll see a blue box marked with a "?". Don't shoot at it (if you have homing missiles or a wide-spread gun, let go of the FIRE key). Try not to die either, or the debris of your ship may hit the box.
Wait until a nearby tank comes out of its base and runs over the box to break it. Taadaa! Out comes your free 1UP!
Invisibility Mode
During the takeoff sequence after stage 5, press CTRL. A textbox at the bottom-right corner will pop out. Type in "go0gleypower" and after the animation (stage 6), you'll remain invisible for 20-30 seconds. Survival guaranteed!
You'll return to normal at around the time you see the ruby (which gives you a 1UP).