You may link the account with "Google, Apple, Facebook etcs" for Defense Derby.
If you have an account linked with SNS on the previous device, you may sign in or play the game with same account on the current device.
However, please note that Android and iOS support different platfrom for each. For Android devices, you may use the 'Google Play' platform. For iOS, you may use the Apple (or Game Center) platform.
If you have lost the SNS account, please contact the customer support below for each SNS.
[Google Play Customer Support]
[Apple Customer Support]
[Facebook Customer Support]
*If you are using a guest account, you may lose the gameplay information and payment history when changing devices.