Very common issue when downloading via a non stable internet connection. This is a Google Play Store issue and can only be resolved by redownloading the game.

Uninstall Sunshine Days, switch to a Wi-Fi connection, and download the game again.

missing_obb_key

If you'd like to confirm the OBB file exists, it can be found at the directory:
Device/Internal_Storage/Android/obb/com.NetspeakGames.Hamlet/
file_location