Kuiper Belt
Manual v0.37 • Jan 2022

TL;DR: Dodge boulders and enemies, clear the levels, and survive as long as possible.
Abstract Kuiper Belt is a cover version of the Atari classic arcade game Asteroids, offering additional features, e.g. shields, power-up items, alien drones, or black holes.

Built for modern browsers on PC.
Rules There is no global win condition.
Just avoid losing ships, and keep shooting at asteroids (to split/destroy them) and enemies.

As soon as a level is free of boulders and enemies (and their bullets), the next level/wave starts.

When the player gets destroyed, the next ship will appear in the center (marked by a dotted circle) as soon as
Space
is pressed.

When reaching the edge, most objects can wrap around: asteroids, player ship, bullets, UFOs, drones, homing missiles, mines, and time bombs.
Others will disappear: black holes, power-ups, and bonus items.

Objects of the same type won't collide, e.g. boulders, power-ups, bonus items, or drones.

Floating objects (power-ups and bonus items) are immune to bullets/missile hits, and won't collide with anything. They'll be destroyed, however, when hit by the explosion of a mine or time bomb.
Keyboard controls
Navigation
↑
: Thrust
←
/
→
: Rotate left / right
↓
: Instant turn
Pg Down
: Hyperjump
Esc
or
P
: Pause (menu)
Defence
End
: Shield
Weaponry
Space
: Gunfire
H
: Homing missile
M
: Mine
T
: Time bomb
E
: EMP
Navigation ::
↑
: Thrust Accelerates up to max speed in the current direction.
Without thrust, the ship will slowly decelerate by itself.
Navigation ::
←
/
→
: Rotate left / right Rotates the ship's orientation (heading/shooting direction) counterclockwise or clockwise, by steps of 3°.
Navigation ::
↓
: Instant turn Turns the ship immediately by 180°, so it faces the opposite direction.
Navigation ::
Pg Down
: Hyperjump The ship jumps (through hyperspace) to a random position, where it materializes with previous orientation and velocity.
Usually performed to quickly escape collisions or bullets, but a risky maneuver nonetheless - the target area might be unsafe as well (unless a Safe jump is available).
Navigation ::
Esc
or
P
: Pause (menu) Pauses the game by showing the menu.
Weaponry ::
Space
: Gunfire The glowing blueish bullets have limited range, but they'll wrap around borders.
Default (no extra power) fire rate is 180 RPM (rounds per minute).

Adding extra power by collecting Gunfire energy enhances the gun's capabilities: Operating the gun will slowly eat up (1 shot = 1 unit) any extra energy, especially when firing continuously.

At every level/wave start, extra power is filled up by 250 units.
Weaponry ::
H
: Homing missile Launches a missile equipped with infrared sensor, attracted by the heat radiation of the nearest hostile vessel (UFO, drone/compound) engine.
Able to wrap around borders, it keeps flying until hitting an enemy, or accidentally colliding with an asteroid.

Only 3 missiles can be operative at a time.

At every level/wave start, 1 missile is added to the inventory (maximum: 10).
It can also be replenished by Missile power-ups.
Weaponry ::
M
: Mine Deposits (at rear side) a mine which is triggered only by colliding with an asteroid or a vessel (player ship, UFO, drone/compound).
Able to wrap around borders, it basically keeps drifting along until contact, where its explosion shockwave will hit all nearby objects within a limited radius.

Only 1 mine can be operative at a time.

At every level/wave start, 1 mine is added to the inventory (maximum: 10).
It can also be replenished by Mine power-ups.
Weaponry ::
T
: Time bomb Deposits (at rear side) a bomb which detonates after 3 seconds.
Able to wrap around borders, it drifts along until countdown ends. Its explosion shockwave will hit all nearby objects within a limited radius.

Only 1 bomb can be active at a time.

At every level/wave start, 1 bomb is added to the inventory (maximum: 10).
It can also be replenished by Time bomb power-ups.
Weaponry ::
E
: EMP Triggers an EMP (electromagnetic pulse) that immediately shuts down all enemy ship systems (engine, weapons).
Affected UFOs/drones then drift passively with their current momentum until reaching a border, by which the stun effect ends.

At every level/wave start, 1 EMP is added to the inventory (maximum: 10).
It can also be replenished by EMP power-ups.
Stats :: Score Accumulates the points for hitting/damaging asteroids and enemies (flying saucers and drones), and for picking up bonus items.

Points are internally stored with decimal places; the value on screen is shown rounded down.

On reaching a 1000 point threshold, another life is added (up to 10).
Stats :: Lives (ships) The player starts with 3 lives upon game start and earns an extra life (maximum: 10) per 1000 points.
Play continues to the last ship lost, which ends the game.
Inventory :: Shields Temporary (duration: 3 seconds) force field, protecting from all incoming damage caused by collisions or hostile attacks.
Such a bubble is activated by pressing the
End
key.

Each new ship adds up to 5 shields (maximum: 10).
Inventory can also be replenished by Shield bubble power-ups.
Inventory :: Safe jumps Applies a free shield when a hyperjump is being performed, so the ship is instantly protected when materializing in the new location.
If the ship was already shielded when jumping, its bubble's endurance is prolonged by 3 seconds.

Each new ship adds 1 safe jump (maximum: 10).
Inventory can also be replenished by Safe jump power-ups.
Asteroids (boulders) All relatively large at level start, they split into smaller parts when being hit by bullets or explosions, until eventually they're destroyed.
Upon splitting, the resulting boulders can shoot off in unpredictable directions.

In the first handful of levels their initial number increases (4, 6, 8, 10) until there's 11 of them from level 5 onwards, much like in the original game.

Smaller boulders tend to have a higher velocity than bigger ones.
Also, the average speed of asteroids will slowly increase from level 6 to 20.

When a player bullet or missile hits an asteroid, score increases according to size: the smaller the boulder, the more points are rewarded:

Largest
~ 1 point

Default
~ 2 points

Medium
~ 5.05 points

Small
~ 8.35 points

Smallest
~ 10 points



Occasionally, they contain a gold nugget.
Black hole These slowly drifting - and naturally pretty hard to spot - phenomena exert a gravitational pull on every object on the screen.
They come in three sizes: small, medium, and large, with the large being the most hazardous.

Unlike real black holes they won't destroy stuff directly, but they do suck everything towards them, which makes trajectory prediction harder, and increases the chance of colliding with something that will destroy.

The large black hole in particular is to be avoided, since it's strong enough to make the player ship stick for a while, which makes it a sitting target for all the other incoming debris.

There's one advantage against black holes, which is that the player's ship is fitted with inertial stabilisers, meaning that when it's still, it'll tend to stay still.
Enemies :: Flying saucer (UFO) Every now and then, one of these alien ships turns up. They're able to wrap around borders, as well as shooting glowing reddish bullets.

Large
20 points

Moves relatively slowly, and initially fires in pretty random directions.

Small
100 points

Joins in after a score of 1000.
Clearly faster than the large one, and shooting more accurately.

As levels increase, so do their frequency, velocities, fire rate, accuracy, and bullet speed/range.
The number of UFOs on screen can raise to 2 in level 10, and to 3 in level 20.

Points are given only when they're hit by a player bullet or missile. Getting destroyed this way, flying saucers sometimes drop power-ups.
Enemies :: Holy drones
4-compound
10 points

6-compound
~ 7.22 points

These peculiar autonomous vessels turn up as a compound of 4 or 6, drifting slowly and passively through space unless they are attacked, or collide with either an asteroid, a saucer, or the player's ship.

Single
20 points

Pair
~ 14.44 points

When being hit, a compound splits into 4 single drones or 3 pairs (which also split when being attacked or collide), all of them starting to chase the player.

As levels increase, so do their frequency and max velocities.
Pairs will at some point reach slightly higher max speed than the player, and single drones are always quicker than pairs.
The number of compounds on screen can raise to 2 in level 20, and to 3 in level 40.

Points are given only when they're hit by a player bullet or missile. Getting destroyed this way, drones sometimes drop power-ups.
Power-ups Helpful items that can be collected by flying into them.
Power-ups are occasionally dropped by enemies (UFOs or drones) when they get destroyed.
Power-ups :: Shield bubble Adds another shield, up to 10.
Power-ups :: Gunfire energy Charges the ship's gun with additional 500 units of extra energy.
Power-ups :: Safe jump Makes another safe hyperjump available, up to 10.
Power-ups :: Missile Adds another homing missile, up to 10.
Power-ups :: Mine Adds another mine, up to 10.
Power-ups :: Time bomb Adds another time bomb, up to 10.
Power-ups :: EMP Adds another EMP, up to 10.
Bonus Sporadically appearing objects that can be collected by flying into them.
Bonus :: Gold Gold may be contained in asteroids, and gets released when small boulders are destroyed.

Cat's gold
120 points

Fine gold
240 points

Picking up a nugget yields 120 to 240 points, dependig on quality: the smaller, the better.
Bonus :: Cosmonaut Picking up such a slowly drifting lost soul yields 100 points.
Tips & Trix
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