Mobile Game Development

Platform-specific patterns for iOS and Android games

Touch Controls

Gesture Recognition

// Touch input patterns
const gestures = {
    tap: { maxDuration: 200, maxDistance: 10 },
    longPress: { minDuration: 500 },
    swipe: { minDistance: 50, maxDuration: 300 },
    pinch: { fingers: 2 },
    drag: { fingers: 1 }
};

// Virtual joystick
class VirtualJoystick {
    private center: Vector2;
    private maxRadius: number = 50;
    
    getDirection(): Vector2 {
        const delta = touchPos.subtract(center);
        return delta.normalize().clampLength(1);
    }
}

Touch-Friendly UI

Minimum touch target: 44x44 points (iOS) / 48x48 dp (Android)
Button spacing: 8-16 points minimum
Avoid: Small buttons, hover states, precise gestures

Performance Optimization

Battery Optimization

Target: 30-60 FPS (adaptive)
When battery low or thermal throttling:
- Reduce FPS to 30
- Lower particle counts
- Disable post-processing
- Reduce physics iterations

Thermal Management

// Unity - Adaptive Performance
AdaptivePerformance.DeviceThermalStateChanged += (state) => {
    switch(state) {
        case ThermalState.Throttling:
            QualitySettings.SetQualityLevel(0);
            Application.targetFrameRate = 30;
            break;
    }
};

Memory Limits

Responsive UI

Safe Areas

// Handle notches/cutouts
const safeArea = Screen.safeArea;
canvas.style.padding = `${safeArea.top}px ${safeArea.right}px`;

Adaptive Layouts

Portrait: Vertical stacking, thumb-friendly bottom controls
Landscape: Horizontal layout, dual thumbsticks
Tablet: Larger UI, more screen real estate

Resolution Scaling

// Dynamic resolution for performance
const dpr = Math.min(window.devicePixelRatio, 2);
renderer.setPixelRatio(dpr);

App Store Guidelines

iOS (App Store)

Required:
- Privacy policy
- App Tracking Transparency (ATT) for ads
- Sign in with Apple (if other social logins)
- Age rating questionnaire

Avoid:
- External payment links
- Mention of other platforms
- Beta/test in screenshots

Android (Play Store)

Required:
- Content rating
- Privacy policy
- Data safety form
- Target API level (current year - 1)

Avoid:
- Deceptive ads
- Misleading screenshots
- Keyword stuffing

Monetization

In-App Purchases (Ethical)

// Consumables: Coins, gems, lives
// Non-consumables: Remove ads, unlock levels
// Subscriptions: VIP pass, battle pass

// Always show real price, not just premium currency
const product = await store.getProduct("remove_ads");
showButton(`Remove Ads - ${product.localizedPrice}`);

Ad Integration

// Rewarded ads (preferred - user choice)
adManager.showRewarded({
    onReward: () => player.addCoins(100),
    onDismiss: () => resumeGame()
});

// Interstitials (sparingly)
// Show between levels, not mid-gameplay
// Frequency cap: Max every 3-5 minutes

Ethical Guidelines

Do:
✅ Rewarded ads (optional)
✅ Cosmetics-only purchases
✅ Clear pricing
✅ No pay-to-win in multiplayer

Avoid:
❌ Loot boxes with real money
❌ Aggressive upsells
❌ Hidden costs
❌ Targeting children

Push Notifications

Engagement (Non-Annoying)

// Good:
// - Daily reward available
// - Friend activity
// - Event starting

// Bad:
// - Come back! We miss you!
// - Buy now!
// - Constant reminders

const notification = {
    title: "Daily Reward Ready!",
    body: "Claim your free gems",
    schedule: { hour: 18, minute: 0 }
};

Cross-Platform Considerations

Unity Mobile

// Platform-specific code
#if UNITY_IOS
    // iOS-specific
#elif UNITY_ANDROID
    // Android-specific
#endif

// Touch input
if (Input.touchCount > 0) {
    Touch touch = Input.GetTouch(0);
    if (touch.phase == TouchPhase.Began) {
        HandleTap(touch.position);
    }
}

Godot Mobile Export

# Touch input
func _input(event: InputEvent) -> void:
    if event is InputEventScreenTouch:
        if event.pressed:
            handle_tap(event.position)
    elif event is InputEventScreenDrag:
        handle_drag(event.velocity)

Testing

Device Coverage

Test on:
- Low-end phone (2-3 years old)
- Current flagship
- Tablet
- Different aspect ratios (16:9, 19.5:9, 20:9)

Checklist

[ ] Touch targets large enough
[ ] Works offline
[ ] Handles interruptions (calls, notifications)
[ ] Respects mute switch
[ ] Battery usage acceptable
[ ] Loads quickly (<5 seconds)
[ ] Handles background/foreground