Stuck on a wave, hit a bug, or just have a question? You're in the right place.
Fully close the app (swipe it away from your app switcher, don't just background it) and relaunch. This resolves the vast majority of stuck-state issues.
Check your phone's physical mute switch, and confirm Sound Effects / Music are both switched on under Settings inside the app. Tapping anywhere in the app once also helps — iOS sometimes needs an initial tap to fully enable audio.
On the title screen, tap REMOVE ADS, then tap Restore Purchases. Make sure you're signed in with the same Apple ID that made the purchase. This re-links a prior purchase if it didn't apply automatically — common after reinstalling the app or switching devices. If the REMOVE ADS button is no longer on the title screen, your ads are already off.
Open the HANGAR from the title screen and tap Restore Purchases under the UNLOCK button. Use the same Apple ID that made the purchase.
Please tell us exactly what wave you were on, what you were doing right before it happened, and what device/iOS version you're using — the more specific, the faster we can track it down.