Snake

Goal of the game

Steer a neon snake that never stops moving. Every fruit makes it grow and scores points. Hitting a wall or your own body costs a life.

Controls

• Keyboard: arrow keys or W, A, S, D to turn; P or Esc to pause.
• Touch screen: swipe anywhere in the direction you want (without lifting your finger you can chain turns) or use the directional pad.
• Quick turns are remembered: you can queue up to three in advance.

Fruit and bonuses

• Fruit: +2 rings. Eat them quickly in succession for a combo multiplier (up to × 4).
• Gold nugget: big points bonus, fades away with time.
• Slow-down: slows the snake for six seconds.
• Elixir: shortens the snake by four rings.

Stages

Ten fruits complete a stage: the next one brings new walls and more speed. At the Relaxed and Normal speeds, the screen edges are wrap-around; after that, they become deadly. You have three lives.

Duel against the AI

The two snakes share the field. A round is won by the first to eat ten fruits, or as soon as the opponent crashes. Two winning rounds win the duel. A head-on collision eliminates both snakes.

About the AI

The AI finds its way with a time-aware A* that knows an occupied square will be freed once the tail has passed. Before following a path, it simulates its body on arrival and checks by flood fill that it will still be able to reach its tail. At Infernal level, it also evaluates the sharing of territory (Voronoi diagram) against your possible replies in order to cut you off. Lower levels make trajectory mistakes that become rarer and rarer.