Neon Serpent

Reading the board in Neon Serpent

The board, the clock, and the two ways to die

The playfield is 600 by 420 pixels divided into 30-pixel cells, which gives you a 20-column by 14-row grid — 280 squares in total. The serpent starts three segments long, heading right, and moves one whole cell per step rather than gliding continuously.

A step ends your run in exactly two situations. Either the next cell is outside the grid, or the next cell is occupied by part of your own trail. There is no wrap-around: leaving the board through the right edge does not return you on the left. Filling all 280 cells is a win rather than a loss, though almost nobody gets there.

The step clock starts at 138 milliseconds and shortens by 0.7 milliseconds for every point you score, with a hard floor at 72 milliseconds. Because each orb is worth ten points, the serpent reaches its maximum speed on the tenth orb and never gets faster after that.

Chasing your own tail is legal, and it is the whole game

The single most useful rule to internalise: on any step where you do not eat, the collision check ignores the last segment. That cell is being vacated as you move into it, so following directly behind your own tail is always safe. Experienced players do not weave around their trail — they tuck in behind it and ride.

This turns the late game into a shape problem rather than a reflex problem. Lay the trail down in tight boustrophedon rows so the empty space stays as one connected region, then follow your own tail while you wait for the next orb to appear somewhere reachable. Trouble starts when you cut the free space into two pockets and the orb spawns in the one you are not in.

• Hug an edge on approach so the orb is collected at a corner, not in open ground where you have to commit to a direction.
• Before turning inward, check whether the gap you are leaving behind is at least two cells wide — a one-cell corridor is a trap once you are longer.
• When the clock is at its 72-millisecond floor, plan the turn after the one you are about to make; there is no time to decide mid-step.

What each orb is worth

Scoring is deliberately flat: every orb is ten points regardless of how long the serpent is, how quickly you reached it, or how far you travelled. There is no combo multiplier and no time bonus, so a 300-point run always means exactly thirty orbs.

Your best score is written to this browser after every orb, not only when the run ends, so a crash or a closed tab cannot cost you a score you already earned. The number beside the live score is that stored best.

Common mistakes

Most runs end for one of four reasons, and only one of them is really about reaction speed.

• Trying to reverse. A direction directly opposite your current heading is rejected outright, so hitting left while travelling right does nothing at all — the input is discarded, not queued, and players often read that as a dropped keypress.
• Buffering two turns at once. Only one direction is held between steps. Pressing up then left in quick succession keeps the left and throws the up away, which is why fast double-taps produce the wrong corner.
• Taking the centre orbs early. Collecting from the middle of the board splits the free space in half. Early orbs are cheap; take them on a route that keeps your trail against an edge.
• Treating the speed increase as endless. It stops at the tenth orb. Runs that end at fifteen or twenty orbs almost always end from a shape error, not from the game outrunning you.

What is different about this version

Orbs never spawn underneath the serpent. The next position is drawn from a list of genuinely empty cells rebuilt after each meal, so you will not lose a run to an orb that materialised inside your own trail.

The step clock is decoupled from the frame rate. Movement accumulates elapsed time and is clamped to 80 milliseconds per frame, so a stutter or a backgrounded tab cannot teleport the serpent several cells forward. Pausing is a first-class state rather than a stopped timer, and the board keeps drawing while paused so you can study the shape before resuming.

Written by the Silverweb Games team from this game’s own implementation. Last reviewed July 31, 2026.