The game works perfectly fine; the problem you describe only affects players using an incorrect version of Joiplay. If you're playing on Android using this emulator, I suggest you read the "Install instructions" section.
I’ve just performed a clean reinstall of JoiPlay on my device to check and make sure that looping animations are working properly, and I can confirm that they are. If you downloaded the emulator and the Ren'Py plugin from the official website (joiplay.net), you should have version 1.20.023 (verifiable by clicking "About" in the top right menu of Joiplay) and shouldn't encounter any problems. Version 1.20.410, available on the emulator creator's Patreon, also works without issue. The only reported problems I've seen are from people who downloaded the unofficial version 1.21. If this is your case, please verify that you have reinstalled both Joiplay AND the official Ren'Py plugin. If your problem persists despite all this, I recommend the APK version, which doesn't depend on a third-party application.