Devlog // Double It
The Black Hole: choreographing the game's most dramatic moment
Once in a while DOUBLE IT eats the entire board and hands back a single number. Making that feel inevitable — not random — took more choreography than any other effect in the game.
Why a black hole at all
Two systems needed the same dramatic beat. The Zero power — the rarest thing the game can deal — devours every number on the ring and births one supreme value. And Zen mode's one-time rescue: when a peaceful run ends, the board collapses and re-emerges smaller, letting the session continue. Both are "the board goes away and something fair comes back." One choreography, two meanings.
Overlapping waves, not a sweep
The naive version — shrink everything toward the center at once — looked like a UI transition, not a force of nature. The shipped version gives every orb three properties: a personal delay (0–0.4 s, so bodies fall in overlapping waves rather than in formation), a personal spin direction and speed (so the spiral has turbulence), and a radius factor that decays with acceleration — slow at the rim, violent at the horizon. Orbs visibly stretch along their fall line, smear into the core only in the final moments, and their digits dissolve as the body is pulled apart. Numbers stop being information and become matter.
Underneath, a gravitational heartbeat pulses — and the interval between pulses tightens as the collapse deepens, from a calm 0.3 s toward a frantic floor. The screen shake grows on the same curve. You hear the event horizon approaching before the last orb crosses it.
The arithmetic of fairness
Every absorbed number adds to a running sum, and the survivor is the power of two nearest to that sum. The player can estimate the outcome before committing — a board worth roughly seven thousand returns 8192 — so the payoff feels earned, never rolled. The born orb is scored through the same combo multiplier as any merge: the black hole is a play, not a cutscene.
Fairness in juice: the more spectacular an effect, the more legible its arithmetic must be. Spectacle with an opaque result reads as the game playing itself.
Filming it
The collapse also became the climax of the game's promo videos, and capturing it taught me a deterministic-filming trick worth sharing: the capture harness virtualizes time — every frame advances the clock exactly 1/30 s before a screenshot — so a choreography that runs on physics becomes perfectly repeatable, at full render quality, with zero dropped frames. The gameplay in the videos is real; only the clock is patient.
DOUBLE IT is playable free in the browser at doubleit.b-smart.xyz — more entries in the devlog.