Stop It
Press when the needle crosses the green arc. Every hit narrows the arc and speeds the needle up. Miss once and it is over.
What got cut in four hours
The first list had combo multipliers, colour stages, sound effects, a failure animation and a leaderboard. What survived is three things: the needle, the arc and the number.
The leaderboard went first. Attaching a server drags in nicknames, validation and cheat handling, and that alone eats four hours. The best score lives in the browser instead. You cannot race other people that way, but you can race yesterday's you.
Sound went too. Generating a waveform is not the slow part — deciding when it should fire is. Instead the arc brightens on a hit and the screen shakes once on a miss. With no feedback at all you cannot even tell the press registered.
The two guards that stayed
Speed is capped. Each hit adds 7.5%, and without a ceiling it passes human reaction time around the twentieth. Past that it is luck, not skill.
The arc has a floor. It shrinks 7% per hit but stops there. Shrink it past what the screen can show and it is not difficult, it is invisible.
A new arc never appears right in front of the needle. Without a minimum gap it can spawn just ahead and sweep past before there is time to decide.
What the format taught me
A four-hour limit does not make you cut features so much as it makes you decide what the core is, first. Here the core is asking "press now?" over and over; everything else either helps that or gets in its way. A combo multiplier might have helped, but there was no time to check, and what I cannot check does not ship.
This one shipped with its hit test inverted
I found out after publishing it. Pressing exactly on the green arc failed, and pressing the opposite side succeeded. The angle difference is folded to a range and then compared against half the arc width — and the comparison was the wrong way round. The arc draws correctly and the needle sweeps correctly, so anyone playing it just assumes they missed.
The browser could not catch it: with the preview pane hidden the animation stalls, so all it could confirm was that the first frame drew. It only surfaced once the rule was pulled out and measured on its own. Ten checks now cover it, including the wrap-around at zero degrees.
You can switch that bug back on in the bug museum: on gives you the comparison exactly as it shipped, off gives you the current rule. That is more precise than saying it is fixed.
Today's order
The "today's order" button above fixes the sequence of target arcs by date, so everyone playing today gets the same one and "I missed on the eighth" means the same thing to both of us. Free mode reshuffles every run.
The date rule is shared with the daily run and the avatar maker. Written separately in each place, they would disagree with each other around midnight.
The next theme is not decided yet. When it is, it shows up here — and the four-hour game page is where suggestions come in.