If the apps/games were obtained through the Google Play Store, you won't need to do anything. Once you configure the Google account on the new phone, log into Play and all your old apps will be available from the "My apps > All" menu. If you obtained them on your S2 from elsewhere, you can use one of the many free backup apps (e.g., App Backup & Restore, JS Backup, MyBackup, and many more).