On this page of the Spider-Man Miles Morales guide you will learn how to start a New Game+.
To start the New Game+, restart the game after completing the last main mission (The Battle for Harlem), choose a save file with the completed campaign and press the square.
When creating NG+, a new difficulty level will be unlocked - MEGA. You will start the game with all the resources, suits, gadgets, skills and character levels. After starting NG+, you will have access to hidden skills, suits and gadget mods. You will now be also able to level up to lvl 30.
The progress of all side activities and collectible items does not transfer to NG+, but you can go back to the base save at any time and finish finding all the collectibles, as well as the district progress.
The New Game+ is a great way to get reacquainted with the game months or years after the first playthrough, without having to worry about finding collectibles, adjusting the equipment or maxing out the skill trees. Insomniac Games introduced several additional benefits and features to encourage players to complete the campaign again. Completing the New Game+ is also necessary to get all the trophies.