It is very important to note that there were two versions of Terraria on Google Play:
"Terraria" -- This is the paid version.
"Terraria Trial" -- This was the free TRIAL version with limited content and the option to buy the full version as an in-app purchase.
Since the 18.104.22.168 update, we are removing the Trial version from the Google Play Store. If you downloaded the Free Trial but did not purchase the full game unlock from the free trial app, you will no longer be able to load the Trial and Tutorial level, and you should only see this screen:
If you have previously purchased the full version of Terraria from within the free app, it will appear as "Terraria Full Version (Terraria)" in your Google Play Order History. If you have this in your Google Play Order History and still see the above screen, please ensure you’re signed into Google Play with the account which made the purchase and connected to the internet. If this doesn’t work we also recommend a reboot of your device.
Once your purchase has been verified for the first time, you should no longer see the verification screen, except when there is an update to the game.
If you can see the game in your order history, but have since uninstalled the game, you can re-install the game from My Apps and Games >> Library and scroll down to Terraria Trial and re-install it from here: