New interactive sim

One tap.
Catch everything.

A universe of moving stars. One spark to place anywhere. Every collision creates another reaction—but when the glow runs out, your score is final.

Choose your spark
Tap the universe

Caught

0/180

Chain

0

Verdict

Tap the universe

Step one

Read the sky

Watch the current until stars drift into the perfect cluster.

Step two

Place one spark

You get one tap. Its expanding wave must make the first catch.

Step three

Watch it spread

Every captured star becomes a new pulse until the universe goes quiet.

Built for repeat attempts, satisfying chain reactions, and vertical video exports.

Simulator guide

How One Tap Chain Reaction
actually works.

One Tap gives you a single decision: where and when to place an expanding spark among moving stars. Each captured star becomes another temporary spark, so one good contact can propagate across the field.

Written by WeSimSims · Last meaningfully updated August 30, 2026

How to use it

  1. 1Watch the moving field before acting.
  2. 2Tap once where several paths are likely to converge.
  3. 3Let the reaction finish, review the score, and try a different timing or location.

What the model demonstrates

The initial pulse expands and then fades. A moving star caught by any active pulse stops and emits its own pulse with the same capture ability, producing a finite collision chain.

Controls that matter

Single tap
Places the only player-created spark for that attempt.
Restart
Clears the completed chain and generates another opportunity.
Export
Captures the setup, cascade, and final score as a vertical sequence.

Experiments to try

  • Tap immediately, then compare with waiting for a dense cluster.
  • Place the spark near an edge and then near the center.
  • Aim for crossing paths rather than the current position of one star.

How to read an outcome

A central tap can reach more directions, but timing matters more than symmetry. Near misses produce no second pulse, while one well-placed catch can bridge separate groups.

Limitations and accessibility

Stars and sparks are abstract game objects. The expansion and collision rules are designed for a readable chain reaction, not chemistry, astronomy, or explosive physics.

Animations may include rapid motion, flashes, synthesized sound, and dense particle effects. Pause playback, mute sound, or reduce graphics quality whenever needed.

Frequently asked questions

How many taps do I get?

One player-created spark per attempt.

Why does the chain stop?

Every pulse has a finite lifetime; the run ends when no active pulse can catch another star.