Signal Snake
ARROWS OR SWIPE
Signal Snake
Grid movement, self-collision, and a food spawner — the oldest game-logic test there is.
Canvas gridSwipe60 fps
Playable prototypes
Five demos, zero downloads.
Every mini-game below runs client-side, ships as a phone-shaped widget, and behaves the same way in this browser as it would in a store build.
Touch, drag, or the arrow keys — whichever this device prefers.
Merge Circuits
ARROWS OR SWIPE — MATCH VALUES TO MERGE
Merge Circuits
A 2048 clone: four-direction slide-and-merge written as pure functions, so the board state is trivially testable.
State machineSwipePure functions
Circuit Match
FIND THE MATCHING PAIRS
Circuit Match
Memory-match with hand-drawn schematic symbols. Tests timing, not reflexes.
SVG iconsAsync state
Reflex Test
TAP WHEN THE SCREEN TURNS GREEN
Reflex Test
Measures input latency in milliseconds — tap the instant the screen turns green.
performance.now()Input latency
Dodge Run
DRAG OR ARROW KEYS
Dodge Run
An endless dodger with a rising difficulty curve — pointer-drag on mobile, arrow keys on desktop.
requestAnimationFrameAABB collision