# Game feel

composing shake, hitstop, punch, flash and particles

```{raw} html
<a class="example-run-button" href="../demos/features_2d_juice.html">▶ Run in browser</a>


```

**Tags:** `2d` `juice` `camera` `coroutines` `particles`

A target sits mid-screen; SPACE hits it. Each hit stacks five "juice"
ingredients: camera shake, hitstop, a damped-sine punch on the target,
a white flash, and a particle burst. Keys 1-5 toggle each ingredient
so its individual contribution can be felt in isolation.


## Why each ingredient works

- Camera shake (`Camera2D.shake`): jolting the whole view sells the impact's
  energy to the eye without moving anything in the scene.
- Hitstop (`App.time_scale`): freezing time for a tenth of a second makes the
  frame of contact linger, which reads as weight. The restore timer runs on
  the wall clock: at a near-zero time scale coroutine dt is scaled to ~0, so
  a scaled `wait()` would never complete.
- Punch (`punch_position` / `punch_rotation`): a damped-sine recoil on the
  target itself says the hit landed on THIS object, not on the camera.
- White flash: a one-frame overlay marks the exact instant of contact, the
  visual equivalent of a click.
- Particles: debris carries the energy outward and leaves an aftermath, so
  the hit has consequences beyond the frame it happened on.

Controls:
  SPACE - hit the target
  1..5  - toggle shake / hitstop / punch / flash / particles
  ESC   - quit

Run: uv run python examples/features/2d/juice.py
Headless self-check: uv run python examples/features/2d/juice.py --test

## Source

```{literalinclude} ../../examples/features/2d/juice.py
:language: python
:linenos:
```