Polaris (video game)

Gameplay

In Polaris, you pilot a submarine that fires missiles straight up. Your mission is to clear each stage by shooting down every airplane while dodging bombs from above, mines launched by enemy subs, and depth charges dropped by passing boats. The game ends when your last sub is destroyed. Your sub can be sunk by touching a projectile, an enemy sub or boat, a depth charge, a mine, the ocean floor, a torpedo, or a reef.

Each stage starts with six to ten small planes in the sky. Half are pink and fly from right to left; the other half are blue and fly from left to right. These planes drop bombs you can shoot and destroy, and they wrap around the screen when they reach an edge. A small plane’s speed changes based on how many of its color remain: a pink plane moves slowest when all pink planes are still alive, and fastest when it is the last pink plane left. Once all small planes are gone, a large plane appears. It follows a complex path, looping across the sky and dropping homing missiles. These missiles fall straight down until they are level with your sub, then move sideways toward it. They cannot be destroyed. Taking out the large plane ends the level.

An enemy submarine moves left to right along the seafloor and fires indestructible red mines upward. Most enemy subs can be destroyed by sliding underneath them and firing a missile up, but each level has one sub that sits very close to the ocean floor and cannot be destroyed. In later levels, a small white sub also appears and is indestructible. Like the small planes, enemy subs wrap around when they reach a screen edge.

A yellow boat moves across the water’s surface, alternating direction. In later levels, the time between boat appearances shrinks until a new boat appears almost instantly after the previous one leaves or is destroyed. When the boat passes over your sub, it drops depth charges you can shoot. If you destroy the boat, it drops an indestructible mine.

You earn a bonus life at 5,000 points. Every three levels, you get bonus points: 1,000 after Level 3, then 1,000 more each time, until Level 27, after which the bonus stays at 9,000 points.