Complete the game with Phobos

To unlock this trophy you must beat the entire Arcade mode from start (Level 1 - Acis) to finish (Level 5 - Mefitis) with the Phobos ship. If you exit the game at any time for any reason the trophy will not unlock, even if you immediately resume playing from the same level. If you lose all your lives and simply continue it will not invalidate the trophy, so don't worry about failing the levels unless you are going for 1CC as well.

Starting from a level other than Acis and then finishing the others will also not work, so be sure to do the following:

Single Player -> Arcade -> Select Difficulty -> Phobos -> Acis -> Clear the game without exiting or turning off your PS4.