Sorry to hear about these issues :(
I admit, the UI elements were not compatible with all devices (It was meant for 1920x1080 resolutions). I did end up figuring out a solution for it and will update it after the voting period ends.
There were settings for the sensitivity however, if you press esc on the game scene you could adjust it to your liking!
Thanks for the feedback, hopefully you'll come back to it in the future!