Frequently Asked Questions

Slumber Drift is a sleep-powered voyage game for iPhone. Your sleep quality each night determines how far your airship can drift the next day. Better sleep means stronger Voyage Power, better Dream Luck, and further journeys through four sky zones. One voyage per day, ~2 minutes of active play.

No. The game works with iPhone-only sleep data. However, Apple Watch provides detailed sleep stages (Deep, REM, Core), which give more accurate Voyage Power calculations. Without a Watch, some stats use estimated values.

The game still works but won't have sleep data to power your voyage. You can connect HealthKit later through Settings at any time.

During onboarding, you set a sleep goal (6h to 9h30m in 15-minute steps). This can be changed anytime in Settings, accessible from the Airship tab.

Each morning, tap Launch Voyage. Your airship drifts through leagues, accumulating crystals and encountering events. Every 10 leagues, you face an encounter — choose to Retreat (keep all crystals) or Press On (risk 30% for greater rewards). The voyage continues until you retreat, fail an encounter, or reach your maximum range.

• Voyage Power — Determines maximum voyage distance in leagues. Based on total sleep, sleep stages, and efficiency vs your goal.
• Dream Luck — Improves encounter success odds. Based on bedtime regularity over the past 7 days.

• The Shallows (Lg 1–49) — Gentle drifting, more caches, fewer dangers.
• The Open Sky (Lg 50–99) — Balanced events, first milestone at Lg 50.
• Fog Archipelago (Lg 100–149) — More tolls and decay, tougher encounters.
• The Edge of Dreams (Lg 150+) — Maximum risk and reward.

Equipment drops at the end of each voyage. Each piece has a slot (Engine, Hull, Compass), a rarity (Common, Rare, Epic, Legendary), and randomized affixes that boost stats like route distance, encounter chance, crystal earnings, or dream luck. You can reroll affixes or sell equipment for crystals.

Tonics are temporary buffs purchased with crystals from the Tonic Shop. They provide bonuses like improved encounter odds, crystal multipliers, or extended routes. Each tonic lasts a set number of leagues and occupies a tonic slot. Free users have 2 slots; Pro users can expand further.

Consecutive days of good sleep (Voyage Power ≥ 0.8) build a streak. Streaks unlock tiered buffs: crystal multipliers, encounter bonuses, and improved rare drop chances. Missing a good night resets the streak to zero.

Yes. The full game loop — voyages, encounters, equipment, tonics, streaks, and milestones — is completely free with no ads and no time limits. Free users get 1 equipment drop per voyage and 8 inventory slots.

Pro ($4.99, one-time) unlocks up to 3 equipment drops per voyage, 24 inventory slots (vs 8), and the ability to expand tonic slots beyond 2. No subscriptions.

An optional way to support development. Three tiers: $0.99, $2.99, and $4.99. No features are attached — it's purely a thank you.

Sleep analysis data only: total sleep duration, sleep stages (Deep, REM, Core), bedtime, wake time, and sleep efficiency. The app reads — it never writes. No heart rate, no steps, no workouts.

No. The app has no server, no analytics, no tracking, and no third-party SDKs. All data stays on your device. Deleting the app removes everything permanently.

iOS 18.0 or later. iPhone only (portrait orientation). iPad is not supported.

Yes. Slumber Drift is fully offline. There are no accounts, no cloud sync, and no network requirements. Everything runs on your device.

Go to Airship tab → Settings → Purchase section → "Restore Purchases". Purchases are tied to your Apple ID and can be restored on any device.