Player Ship Appearance:

• Your ship must be either a nice-looking sphere (left image above), or a nice-looking sphere with a "mouth" (middle image above), depending on variant.

• For mouth ships, the mouth gap must be no more than 3/4 of the diameter of the ship. The middle image above shows a ship with such a mouth.

• The mouth can be any shape. I have used a cirle in the images because it was easy to draw.

• Mouth collision: Test if the point on the circumference is within the enemy ship's circle. The right image shows a small yellow star where the circumference point would be.

Player Ship Motion:

• Your ship moves by expelling tiny spheres opposite to the direction of motion. As Isaac Newton said: Every action has an equal and opposite reaction.

• The mass of the player's ship is equal to its area. Expelling small masses decreases the mass of player's ship, and thus its area.

• Clicking the mouse left button sets the direction in which the mass is expelled. When the mouse is pressed, construct a vector from the player's ship to the mouse location.

• The mass expelled is 1% of the mass of player's ship.

• The expelled masses join the collection of masses floating around in the play area. That is, they become enemy ships!

There are many instances of an enemy ship in the play area. Each enemy ship interacts with all of the rest of enemy ships and the player ship.

Enemy Ship Appearance:

• Each enemy ship is a circle.

• Each enemy ship starts with a random area.

• Enemy ships are red if bigger than the player's ship, and blue if smaller.

Enemy Ship Motion:

• Each enemy ship starts with a random velocity.

• Enemy ships drift passively.

The primary variations of this game are how the enemy ships in the scene move and respond.