-Estimated trophy difficulty: 8.0/10
-Offline: 40 (26, 10, 4)
-Approximate amount of time to Platinum: About 35-60 hours, depending on the number of playthroughs you need and how quickly you master the events.
-Minimum number of playthroughs needed: 2
-Number of missable trophies: 5 (Half-Truths, Mankind Is Your Mask, Nice Guy, Hard To Kill, and Return Fire)
-Glitched trophies: 1 (Pt)
-Do cheat codes disable trophies?: No
The trophy difficulty has been decided by the users in the Trophy Difficulty Thread, which you may view here: Platinum Difficulty Thread
Introduction: Welcome to [PROTOTYPE], a game that's all about having all kinds of various fun as Alex Mercer, a man who woke up in a morgue with supernatural abilities and only one clear thought in his head: revenge. The following road map and guide will walk you through the steps needed to obtain the Platinum Trophy in the quickest and most painless way possible.
It is possible due to a glitch to miss out on the Pt trophy, but thankfully it's easy to avoid. The glitch occurs if you obtain Platinum Medal scores in all of the events before you unlock the Au trophy. To avoid this and make sure you can get Pt, simply make sure that you have at least one event that you have not obtained a platinum level score on before you unlock Au. As long as you have at least one event that stays at Gold when the game gives you the option to go for platinum scores, you will not have any problems. Thanks to blymberry for discovering this and bringing it to my attention.
Please note that this is actually very unlikely to happen to you unless you specifically look up the times for Platinum Medals and try to achieve them before unlocking Au. The Platinum Medal times and scores are very hard to achieve and you aren't likely to get them right away, so long as you just focus on getting all Gold Medals first and then worry about Platinum Medals later once you have all the Gold ones, you should be fine.
The only cheat code this game has simply allows you to unlock Alex's "Body Surf" attack without spending any EP on it, and will not disable your ability to earn trophies. To use this cheat, on the game's Main Menu, select Extras and then Cheat Code, and enter Right, Right, Left, Down, Up, Up, Up, Down.
And now, onto the meat of the map and guide. Let's play [PROTOTYPE]!
Step 1: Medium Playthrough
You will need to play on medium to unlock hard mode, so that will be our first order of business. Do not start on easy as you will not unlock hard mode that way. It should be simple enough to learn how the game is played as the game does a good job keeping you informed of how to use Alex's abilities. However, you will want to keep aware of the 5 missable trophies, as it's much easier to get them now than it is on hard mode. The easiest one to get is Nice Guy, which requires you to complete the game with 10 or less Civilians consumed. This should be fairly easy to get as there are plenty of military personal and infected to consume when you need health.
The next two, Half-Truths and Mankind Is Your Mask, both require you to complete a certain number of missions without raising a military alert (1 and 3 respectively). Hard To Kill requires you to complete the game without dying. Check the trophy guide for strategies on these, but the big thing to keep in mind if you want to get these now is to save before you start every mission, and should you die or raise an alert on a mission where it's possible not to, quit back to the main-menu and reload your most recent save to try again. Finally, Return Fire requires you to catch an item throw at you by a Hydra and throw the item back at it, which can only be done during the story. Check the trophy guide for more detailed information on when you can do this (thanks to DJDK-ec for pointing out you can miss this trophy).
Once you complete the story missions, you will move on to...
Step 2: Free Roam
The city is now your playground and you may do as you please. In this step you will be going for all remaining trophies that are not Revenge Revisited. Obtain all of the collectable items throughout the city, complete all the various events, complete the various killing trophies, and more. Please refer to the guide for information on how to unlock all the various trophies available to you in this step.
Step 3 (optional): New Game +
Whether you need this step or not, once you have all the other trophies, you are ready for...
Step 4: Hard Mode
And that's about all there is to [PROTOTYPE]. The game will throw a few tough challenges at you (I'm looking at you movement events), but if you keep at it, you should be able to best this game and get a shiny Platinum trophy. Best of luck!
[PST would like to thank mjc0961 for this Road Map]