A multi-stage static-screen shoot-em-up, Moon Cresta was one of the first (if not the first) games to allow powerups, by permitting you to dock up to three levels of your ship together to dramatically increase your firepower. Gameplay is simple: the only controls you have are move left, move right and fire. Your objective is simply to destroy all the alien ships on screen and advance to the next stage. In the docking stage the fire button is used to control your thrusters, should you need to move your ship back up the screen while attempting to dock.
Points are awarded for destroying the alien ships, and for docking the various segments of your ship together. This is allowed each time you clear the fourth and eighth wave of aliens. There are eight attack waves of aliens per level, plus the asteroid and docking stages.
The first two waves consist of four circular alien ships, which break in two and both halves move around the screen. You can only shoot one half of a ship at a time, and there are eight half ships to destroy. The only difference between stages 1 and 2 are the colour of the attacking ships.
Attack waves three and four consist of eight alien ships resembling large insects, which swarm around the screen.Once you clear these two waves you get the chance to dock two segments of your ship together, providing you have at least two lives remaining. You have thirty seconds to land your ship on top of the next segment and they then combine to provide you with greater firepower (and a larger surface area to protect).
The next two waves are made up of larger alien ships which move more quickly. Again there are eight aliens to destroy on each level. These alien ships are also equipped with a stealth capability. If you do not destroy the last couple of ships fast enough on these stages, they disappear and reappear while moving, diving after your ship.
The next wave does not have alien ships to destroy. Instead it consists of sixteen large asteroids which fall diagonally from the top of the screen. The asteroids must be shot or avoided. Survive this stage, and you then have the chance to dock your ship once more, landing the remaining segments on the third stage of your ship. This gives you maximum firepower, and of course a much larger surface area to protect.
You then have two more waves of attacking aliens to deal with. This time they start small and then transform into deadly missiles which hurtle straight down the screen at you. There are again eight alien ships to destroy on each wave, and if you survive these two waves you advance to the next level, the same attack waves but more difficult.
On the third round the last alien on each stage goes into a berzerk mode and starts moving extremely fast making it very difficult to shoot.
An extra life is awarded for 30,000 points.
Stage 3 & 4 Alien: 30 points.
Stage 5 & 6 Alien: 60 points.
Stage 7 & 8 Alien: 100 points.
Asteroid: 200 points.
Docking Stage 1 onto Stage 2: 100 points x seconds remaining.
Docking Stage 2 onto Stage 3: 200 points x seconds remaining.
Docking Stages 1 and 2 onto Stage 3: 300 points x seconds remaining.
Be careful at the corners of the screen. Aliens will sometimes move directly down to the corners, and are difficult to avoid.
The asteroid stage is followed directly by the second docking stage. Count the asteroids and try to be close to the centre of the screen after the last asteroids fall.
Aliens which circle just off the bottom of the screen will sometimes move back into the gameplay area. Watch out below!
When alien ships move off the bottom and do not return they will reappear in their normal start position. A carefully placed shot in the centre of the screen will destroy them as soon as they appear.