Campaign

Fifty levels with walls, corridors and pillar fields. Every one is verified solvable before it ships.

What it does

Campaign gives the snake somewhere to be. Each level has a fixed layout of obstacles, a target number of fruit, and its own starting speed. Clear it and the next unlocks.

How it works

  1. PLAY → CAMPAIGN, then pick a level.
  2. Levels you have cleared are filled in; the next one has a heavy border; locked ones are dimmed.
  3. Eat the target number of fruit without hitting a wall, an obstacle or yourself.
  4. Cleared levels can be replayed at any time — progress never goes backwards.

The difficulty curve

Apple count and speed alone flatten out fast, so the second axis is the shape of the obstacles. The campaign moves through named bands:

Levels Shape
1–2 open board — learn to steer
3–10 single walls
11–19 mirrored block pairs
20–29 pillar fields, tightening
30–39 corridors with a single gap
40–50 mixed, densest

Every level is provably solvable

Levels are generated from a difficulty curve and then checked before they ship: a flood fill from the snake’s starting cell must reach enough free space for the target, the start must not be walled in, and no free cell may be sealed off — because fruit could otherwise appear somewhere the snake can never reach.

The check runs again in continuous integration, written independently of the generator. Two implementations that must agree; if they ever disagree, the build fails. An impossible level 37 is the sort of thing a player finds, in a review.

Known limits