Snake

Entry: main menu g → Games page 2, 1

Classic Snake on a 40 × 20 grid. The body fades from bright head to dark tail so the direction of travel is obvious, and every fifth normal fruit spawns a timed golden one. Wall mode and wrap mode keep separate high scores.

Screenshots

Shortcuts

Key	Action
; , . / / arrows / EASD	Steer (also starts the game)
Space / GO	Pause / resume; replay after game over
r	New game
m	Toggle WALL (die on impact) / WRAP (pass through) — starts a new game
i	Toggle IMU tilt steering (also recenters the neutral pose)
- =	Speed level 1–5
h	Help
ESC / GO	Back to the game shelf

How it plays

• Scoring: a normal fruit is +1, a golden fruit is +5. Golden fruit lasts 7 seconds and blinks during the last 2.
• Ramp-up: each normal fruit shortens the step interval by 3ms down to a 55ms floor. - / = sets the starting level.
• Turn buffer: two direction presses inside one step are queued, so sharp right-angle turns are never swallowed. Reversing 180° is blocked.
• Top bar: S score, L length, B best score for the current mode, plus mode and speed level on the right. A gold IMU badge lights up next to the best score while tilt steering is active; on boards without an IMU, pressing i briefly shows a red NO IMU.

IMU tilt steering

Press i to steer by tilting the device. Keyboard steering keeps working, so you can mix both.

• Neutral pose: the pose you hold at the moment you press i becomes the "centre", so the device does not need to be level. If you change how you hold it, press i twice to recalibrate.
• All four directions have symmetric range: detection uses the angle the gravity vector has rotated away from the calibrated pose, not the raw reading of a single axis. Even with a steeply held device, tilting further the same way never runs into the ±1g end of the range, so every direction stays reachable.
• Direction mapping: tilt up to go up, tilt right to go right. Screen-right is derived from "screen-up × the gravity direction at calibration" instead of being hard-coded to a body axis.
• Sensitivity: a turn needs roughly 9° of rotation and only releases below roughly 4.5° (hysteresis), and one axis has to dominate — this keeps a diagonal grip from flapping between directions.
• Timing: a turn fires only when the tilt direction changes, so holding a tilt does not retrigger. Tilting on the start screen also starts the game.
• Tilt dot: the small box right of the IMU badge holds a dot that follows your tilt, so you can confirm all four directions register.

Records

High scores are stored per mode in /snake_rec.dat on flash — one for WALL, one for WRAP. The start screen shows the best score and total games played.