$npx -y skills add rshankras/claude-code-apple-skills --skill game-feelGame feel ("juice") for Apple apps — celebration choreography, haptic vocabulary design, sound-effect layers, and the event×channel feedback audit. Use when big moments fall flat, when designing haptics or SFX, or when auditing whether every meaningful event actually reaches the
| 1 | # Game Feel (Juice) |
| 2 | |
| 3 | Makes an app's meaningful moments *land* — through coordinated motion, haptics, and sound. Animation technique lives in `design/animation-patterns`; confetti/badge generation lives in `generators/milestone-celebration`. This skill is the **discipline layer**: which events deserve feedback, on which channels, and how to verify nothing important is silent. |
| 4 | |
| 5 | ## When This Skill Activates |
| 6 | |
| 7 | Use this skill when the user: |
| 8 | - Says the app feels **flat**, **lifeless**, or "lacks juice/polish/delight" |
| 9 | - Wants **celebrations** designed (winners, streaks, reveals, score changes) |
| 10 | - Asks to design or review **haptics** (vocabulary, Core Haptics, `.sensoryFeedback`) |
| 11 | - Asks about **sound effects**, buzzers, countdown ticks, or fanfares |
| 12 | - Wants a **feedback audit** — do the right events fire the right channels? |
| 13 | - Is building a **party/group game** where the phone is shared, passed, or watched at a distance |
| 14 | |
| 15 | ## Core Principles |
| 16 | |
| 17 | ### 1. Channels have different reach — match the channel to the audience |
| 18 | |
| 19 | | Channel | Who perceives it | |
| 20 | |---------|------------------| |
| 21 | | Haptics | Only the person **holding** the device | |
| 22 | | Screen motion | Whoever is **looking** at the screen | |
| 23 | | Audio | The whole **room** | |
| 24 | | Torch / flash | The whole room, even in noise | |
| 25 | |
| 26 | A single-user utility can lean on haptics. A shared-phone or room-facing app (party games, kitchen timers, presentations) **must** put its signature moments on a room-scale channel. The most common juice failure: all feedback is haptic, and the phone is lying on a table. |
| 27 | |
| 28 | ### 2. Feedback scales with rarity |
| 29 | |
| 30 | Tick < action confirmed < success < round complete < **winner**. If the rarest event (winning) fires the same pattern as a routine one (round end), the app has no climax. Reserve the biggest pattern, the confetti burst, and the fanfare for the rarest event. |
| 31 | |
| 32 | ### 3. Escalation must agree across channels |
| 33 | |
| 34 | If the timer's ring turns amber at 10s and red at 5s, the haptic tier and any audio tick must escalate at the *same* thresholds. Cross-channel disagreement reads as broken, not layered. |
| 35 | |
| 36 | ### 4. Single-owner rule |
| 37 | |
| 38 | Exactly **one** code layer fires feedback for a given event. When an engine *and* a view-store both react to "music stopped", the user gets a double-buzz. Decide the owner (usually the layer closest to the state machine) and make the other layer silent. |
| 39 | |
| 40 | ### 5. Juice amplifies meaning — it never decorates |
| 41 | |
| 42 | Every effect must be attached to an event the user cares about. Ambient/always-on effects (background particles, looping glows) are *texture*, not feedback — keep them static or slow, and never let them compete with event feedback. |
| 43 | |
| 44 | ### 6. Every channel needs an accessibility story |
| 45 | |
| 46 | - Motion → gate large-scale motion on Reduce Motion, with a static equivalent |
| 47 | - Haptics → user-facing toggle (the system provides no global haptics setting for Core Haptics) |
| 48 | - Sound → mute toggle independent of system volume; a deliberate, documented silent-switch policy |
| 49 | |
| 50 | ## Decision Tree |
| 51 | |
| 52 | ``` |
| 53 | What do you need? |
| 54 | │ |
| 55 | ├─ Which events should have feedback, and on which channels? |
| 56 | │ └─ → feedback-audit.md (event×channel matrix + three-lens audit) |
| 57 | │ |
| 58 | ├─ Design or review haptics (vocabulary, service architecture, APIs) |
| 59 | │ └─ → haptic-design.md |
| 60 | │ |
| 61 | ├─ Add a sound-effect layer (assets, latency, AVAudioSession coexistence) |
| 62 | │ └─ → sound-design.md |
| 63 | │ |
| 64 | ├─ HOW to animate a celebration/transition you've already decided on |
| 65 | │ └─ → design/animation-patterns (springs, transitions, symbol effects) |
| 66 | │ |
| 67 | ├─ Generate confetti / badge / milestone UI code |
| 68 | │ └─ → generators/milestone-celebration |
| 69 | │ |
| 70 | └─ Animated SF Symbols for feedback moments |
| 71 | └─ → design/sf-symbols (preset vocabulary) |
| 72 | ``` |
| 73 | |
| 74 | ## Review Checklist |
| 75 | |
| 76 | When reviewing an app's game feel, verify: |
| 77 | |
| 78 | - [ ] **Signature moments hit ≥2 channels** (e.g. winner = motion + haptic + sound) |
| 79 | - [ ] **Room-facing events use a room-scale channel** (audio, display-size motion, torch) |
| 80 | - [ ] **Rarity gradient exists** — the rarest event has visibly/audibly the biggest feedback |
| 81 | - [ ] **No channel disagreement** — escalation thresholds match across visual/haptic/audio |
| 82 | - [ ] **Single owner per event** — no double-fire from two layers |
| 83 | - [ ] **Score/number changes animate** (`.contentTransition(.numericText())`) — values never teleport |
| 84 | - [ ] **State changes transition** — no hard cuts between phases of a flow |
| 85 | - [ ] **Reduce Motion parity** — every gated effect has a static equivalent conveying the same information |
| 86 | - [ ] **User controls exist** — haptics toggle; mute toggle if there's an SFX layer |
| 87 | - [ ] **Loading/waiting states have anticipa |