Moon Cresta is an arcade game released in 1980. It also appeared in modified form as Eagle.
You control a three-sectioned ship that starts off the game launching its smallest front section, which is followed by its middle section and then by its back section when all the other sections are destroyed. In the first two waves of every level, you face off against four eyes that float around in figure-eights as they descend. Hit one of them and it turns into a half-eye. Hit at least two eyes or four half-eyes and they will squiggle their way toward you, swirling their way back onscreen for another assault. In the next two waves, you face off against eight flies that also squiggle their way toward you in the same pattern as the eyes, again swirling their way back onscreen when they disappear.
Following these four waves, if you still have at least two of your ship sections intact, you will engage in a docking sequence where you must carefully steer your ship section on the top part of another without running out of time or colliding with that section. With successful docking you get bonus points and increased firepower and range.
Then comes the next two waves: eight birds that fly in the same pattern as the eyes and flies, but this time materializing within the middle portion of the screen when they disappear. This is followed by two waves of fireballs, two of which fall at the same time in diagonals. Here you do not need to shoot any of the fireballs to survive the waves.
Finally, after another docking section if you still have ship sections intact and not docked with, come the final two waves of divebombing aliens called Atomic Piles. These move so fast that they are difficult to dodge. Shoot all of them and you'll start the new level with your smallest ship section again, starting with the first wave. From that point on, the game will increase with difficulty, particularly with the Atomic Piles divebombing more frequently.
The scoring is as follows:
- Eyes (Break in half): 50 points
- Eyes (Destroy other half): 100 points
- Flies: 30 points
- Birds: 60 points
- Fireballs: 200 points
- Atomic Pile: 100 points
Docking is a big way to increase the player's score. They get the time remaining from 30 seconds multiplied by 100 for their docking bonus.