I would like to buy the Outlast Trinity bundle for the Ps4 on Amazon in the near future. Single player games can usually be played on the Ps4 without a PS plus membership. I still want to be sure and know whether I can play the game without PS plus.
Here you have your confirmation:
Since it's a single player game, you don't need a PS +. You only need PS + for multiplayer games. Exceptions are free to play multiplayer games - these can also be played online without PS +.