With your new device, when the game shows you the purchase screen, simply select the unlock option again and the game will give you the message "You already have this item". Also make sure you are using the same account you bought the game with.
Oddmar saves your progress, please check if you have the necessary storage permissions in the settings of your device. You can also change the control scheme to on-screen buttons from the settings menu if you prefer to play the game in this way.
To start a new game, please go to your device settings and clear the data of Oddmar, then go to your Google Play Games app and delete the Oddmar cloud saves from there too. After clearing this data, you can start a new game without your older saves.
Clear the cache of your device, the cache of “Google Play Games”, “Google Play Store” and “Oddmar”, then reboot the device. After rebooting, try to buy the game again. Also make sure you are using the latest version of the Google Play Games app.
Clear your device's cache and restart it. Try to buy again after restart. Make sure you are using the latest version of Play Games. If you use multiple accounts on your device, disable those you don't use. Only use your main account.
Try to change the Storage Permission of Oddmar to "On" from your device's "Apps" menu. Then start the game again and see these steps has solved your problem. If not please contact us from our support e-mail and we'll try to determine the problem.