Get Apple TestFlight: Download the official, free TestFlight app from the App Store on your iPhone. TestFlight is Apple's official platform for distributing pre-release software securely. Make sure your device is updated to modern system software (iOS 27+, iPadOS 27+, macOS 27+, watchOS 27+, or visionOS 27+).
Tap "Join Beta" on CodeWing: Return to this page and tap the Join Beta button above. Safari will trigger the official TestFlight invitation link. If prompted with "Open in TestFlight?", tap Open.
Accept Developer Invitation: TestFlight will launch and display the latest build notes and tester information for GOSU Online. Tap Accept to register your Apple Account into the beta testing group.
Install & Start Testing: Tap Install (or Update) to download the build directly to your device. You'll receive instant notifications inside TestFlight whenever Metin Yucel pushes new builds, bug fixes, or feature updates.
Essential Beta Testing Tips:
Apple 10,000 Tester Cap: Apple limits public TestFlight groups to 10,000 active users. If slots are currently full, tap Get Slot Alerts above to be notified the second a slot opens.
100% Free Sandbox Purchases: In-app purchases, subscriptions, and pro features in TestFlight are simulated in Apple's sandbox environment at $0.00 — your Apple Account is never billed.
90-Day Build Lifespan: Each build expires after 90 days. Developers periodically push updates that reset the countdown, and your personal app data is preserved.
Revert to App Store Anytime: You can switch back to the public release at any time by redownloading GOSU Online directly from the regular App Store.
About GOSU Online
FINALLY!
Fireboy and Watergirl is available! and it's ONLINE! Worldwide!
Fireboy and Watergirl is an addicting TEAMWORK and fun game for two players. Help Fireboy and Watergirl to find the exit through the Forest Temple. Fireboy must avoid the water and Watergirl must avoid the fire, and be careful, the green mud kills them both! You can collect diamonds for extra points!
Features:
Single player mode: Now you can play all levels by yourself tapping on character icon to switch between Fireboy and Watergirl.
Cross-platform is available! Now you can play with all mobile devices!
All levels are updating frequently. We suggest that you check the game every day and don't miss any updates and new levels! (You must re-start the app to check daily updates!)
Notes:
Because of this is an online multiplayer game, you can play with a Game Center account which is logged in OR you can play without a Game Center account, as a Guest too!
We always care about and read our players' reviews/feedbacks and try to improve our app in this direction. Please continue to share your positive and negative comments. :)
You can try to delete and re-download the app if something wrong happened. :(
How do I join the GOSU Online TestFlight beta on iOS?
First, download Apple's official TestFlight app from the App Store on your iPhone. Then return to this page and tap the "Join Beta" button above. Your device will automatically open TestFlight and prompt you to accept the developer's beta invitation. Tap "Accept" and then "Install" to start testing GOSU Online. If it says "This beta is full", tap "Get Slot Alerts" to be notified instantly when a slot opens.
Is testing GOSU Online on TestFlight safe and free?
Yes, testing GOSU Online is 100% safe and free. Every public TestFlight build must strictly follow Apple's App Review Guidelines and passes Apple's automated and manual security checks before public invitation links can be distributed. All betas operate within Apple's secure operating system sandbox and cannot access your device data without explicit permission. The beta is developed and maintained by Metin Yucel.
Do in-app purchases or subscriptions cost real money during TestFlight beta testing?
No. In TestFlight, Apple connects all transactions to its free Sandbox environment. Any in-app purchase, pro feature tier, or subscription inside GOSU Online will display "[Environment: Sandbox]" and costs $0.00. Your Apple Account or credit card will never be billed for purchases made within a TestFlight beta build.
Does GOSU Online work on iOS 27 and the latest iPhone models?
Yes, GOSU Online is fully compatible with iOS 27 and iOS 26 across modern iPhones, including iPhone 18, 17, 16, 15, and 14 series. It supports modern iOS 27 capabilities including Siri AI, Dynamic Island, Lock Screen widgets, StandBy mode, and Apple Intelligence where applicable.
What should I do if the GOSU Online TestFlight beta says "This beta is full"?
Apple enforces a strict cap of 10,000 public testers per TestFlight app. Popular betas fill up quickly, but spots reopen regularly because Apple automatically purges inactive testers, and Metin Yucel frequently clears inactive seats before dropping new beta builds. Tap the "Get Slot Alerts" button on this page to receive instant Email and Telegram alerts from CodeWing the moment an open slot is detected. You can also discover trending alternatives in the Games category.
Will installing the beta replace my current App Store version of GOSU Online, and will I lose my data?
Installing the TestFlight beta will replace the App Store version on your iPhone, but all your local app data, documents, logins, and configurations are safely preserved. If you ever want to switch back to the stable public release, you can simply redownload GOSU Online directly from the App Store at any time without losing your data.
How long does a TestFlight beta build last before it expires?
Each TestFlight build has a maximum lifespan of 90 days from the day the developer uploaded it to Apple. You can see the countdown days directly beneath GOSU Online's title in your TestFlight app. Developers regularly release new builds with improvements, which automatically resets the 90-day timer so your testing is uninterrupted.
How do I send feedback or report bugs for GOSU Online?
You can send feedback directly to Metin Yucel by taking a screenshot while using GOSU Online and tapping "Share Beta Feedback", or by opening TestFlight, tapping GOSU Online, and selecting "Send Beta Feedback". You can include notes, screenshots, and system logs to help the developer fix issues before the official App Store launch.
