Using Cross-Save can "pop" trophies on the second device. If you earn a Platinum on PS3 and download that save to your Vita, the corresponding Vita trophies will often unlock automatically, giving you two Platinums. Manual Backup and File Locations

You can manually save by pausing the game, navigating to Options , and selecting the save button.

The PS3 and Vita versions are identical, but the save file size is larger on PS3. When transferring from PS3 to Vita, the game must recompile the map data. Do not turn off your Vita during the "Compiling..." screen, or you will corrupt the save.