UPDATE: GRIS developer Nomada Studio responded to this report citing that these issues are Bluetooth related. See below:
Hey! Yes some people reported issues with bluetooth headphones and speakers, it could be related sorry about that, we’re currently investigating it
— Nomada Studio - G R I S (@nomadastudiobcn) August 22, 2019
You may or may not have seen that Devolver Digital just released GRIS on the App Store, but we wanted to do a quick public service announcement to say that you might not want to hop on buying it just yet.
The puzzle platformer has come to small screens looking pretty great and running at a solid 60 frames per second, but it's got some glaring technical issues, most notably an audio bug that generates high-pitched digital noise instead of the game's audio. This noise comes suddenly and can blast out at a volume that's quite uncomfortable to listen to.
There are also times where the mobile version of GRIS stops responding to inputs or misplaces prompts on screen to the point that you can no longer make progress. Force restarting the game can fix these issues, but they're all fairly significant problems.
Throughout our time with GRIS, these were the only issues with the game. It's also possible Devolver will release an update in short order to address these issues. In either case, I'd hold off on buying the game for the time being if you plan to play it with Bluetooth headphones or a controller. For more info about the game itself, check out our review.