Assembling and bringing to release a finished game on Unity (Android) with fixing critical bugs, profiling and publishing on Google Play

Initial situation: there is an almost finished mobile game (casual 2D runner) on Unity 2022.3 LTS. The project was inherited from the previous team, is now compiled in Editor, but is unstable on real Android devices. The game already has levels, UI, RU-EN localization, Firebase analytics, advertising networks (Unity Ads + AdMob via mediation), in-game purchases through Unity IAP, and progress saving. It is necessary to bring the project to a state where it can be reliably released on Google Play.

Technical environment and subject area: Unity 2022.3 LTS, URP 2D, C#, Addressables (partially), Android API 33-34, Gradle, IL2CPP, Firebase SDK, Google Play Billing v5+, Git. The build is done via Android Studio/Gradle, signed via upload key. The project is stored in a private Git repository, we will give access.

What needs to be done (steps):
1) Project audit and problem reproduction on 2-3 target devices (at least one weak device with 3-4 GB RAM level). Make a short list of causes and a plan for correction.
2) Fix crashes and freezes: according to logcat/Unity/Android logs (typically NullReference in UI flow, problems with the ad life cycle, errors when restoring purchases, rare ANRs when loading a scene).
3) Bring monetization into working order: interstitial advertising, rewarded, banners - without blocking control and without leaking event subscriptions. IAP - correct processing of purchases and restorations, no duplicate charges.
4) Performance optimization: reduce FPS drops and memory spikes when changing scenes/levels. Use Unity Profiler/Memory Profiler, eliminate explicit allocations in Update, heavy Canvas rebuild, unnecessary Instantiate/Destroy. If necessary, configure Addressables correctly or replace problem areas with simpler loading of resources, but without rewriting half of the project.
5) Prepare a release build: configure Player Settings for Google Play (IL2CPP, target architectures, min/target SDK), fix Gradle dependencies and AndroidX/Jetifier conflicts, check the correctness of permission. Build AAB, check install/update over the previous version.
6) Minimum final quality control: checklist for completing 10-15 minutes of play, checking advertisements, purchases, saves, language changes, behavior when going into the background and returning.

Specific result: a submitted Unity project in the repository with fixes, a release AAB for Google Play and a short file RELEASE_NOTES.md describing the changes made and known limitations.

Restrictions: you cannot change the game design, add new levels or make new art. Only code edits, settings, SDK integrations, optimizations and fixes are allowed. You cannot connect third-party paid assets without approval. All changes should be in the form of commits in Git with clear messages.

Measurable acceptance criteria:
- The release build (AAB) is installed on Android 10-14 and does not crash at startup, within 20 minutes of continuous play - 0 crashes.
- No ANR when loading levels and returning from the background (check for at least 10 collapse-expand cycles).
- Rewarded advertising: display by button, correct issuance of a reward, no more than 1 unsuccessful impression out of 10 attempts with a stable Internet connection.
- Interstitial: display at specified points, after closing, control returns, the UI does not freeze.
- IAP: the purchase of a test product passes, when restarted, the purchase is restored, charges are not duplicated.
- Average FPS on a weak device is not lower than 45 in gameplay (excluding the first 3 seconds after loading the scene), no regular freezes longer than 200 ms (estimated by Unity Profiler/Android frame timing).

Access and materials: we will provide a repository, Firebase/AdMob/Unity Ads test keys, a list of target devices and current steps to reproduce problems. It will be necessary to maintain short interim reports on stages.