I've had no issues transferring my game to a new phone. I have an Android device. All of my gameplay is saved to my Google Play account automatically. It's been awhile, but when I transferred to my new device, I don't even think I had to do anything- it just loaded the info automatically when I started the game. If it doesn't do that, you can go into settings and connect to different types of accounts to get your gameplay back.
Yeah it did just what I was afraid it would do. Started over. I tried hitting the Google connect button which did nothing. When logged into the original gameit showed me the original file with a title of "Local Data" & a "Keep this" button, the new file with the Google Play header & a "Transfer to this" button, & a "Merge together" button. I was afraid to try the merge option so I kept the original file. Has anyone else run into this & tried the merge option?