-Estimated trophy difficulty: 3/10
-Offline: 46 (36 Bronze, 5 Silver, 4 Gold, 1 Platinum)
-Approximate amount of time to Platinum: 9-15 Hours if you go for Remember the Heroes trophy first time through, otherwise you will have to start a new game and replay the entire single player for this trophy which will add another few hours playtime.
-Minimum number of playthroughs needed: 1 if following this guide, 2 if you don't get Remember the Heroes first playthrough
-Number of missable trophies: 5 (Team Spirit, Team Victory, Team Glory, Team Supremacy, Remember the Heroes)
-Do Cheats Disable Trophies?: Yes
Quickest Way To Platinum:
For the quickest way to platinum Monsters Vs Aliens follow these steps to get the trophy. Platinum can be achieved in a different order, but that may cause you to have to play the game more then once and take longer then if you follow these steps.
When you first start, make sure your focus is on not failing (dying) so you get the secret "Complete the game without failing more than ten times" trophy. If you do fail you should exit out of the game and restart completely. If you simply quit the stage you're on it will still save your game, which would be counting against your total number of times failed.
Focus on not failing the entire game and just beating it your entire playthrough. Otherwise, if you do fail more than ten times you will have to replay the entire game a second time to get this trophy.
Complete all the levels up until Pursuit (Chapter 1, Scene 4). Once you have beat that level go into the DNA Lab and advance to the spot where you are allowed to buy Ginormica's Chain Dash ability. This will help you through all her levels later in the game. After her ability is purchased you can play straight through the rest of the game until you beat it. Don't forget to watch the entire credits after you beat the game for the "Stay Put and Watch" trophy.
You can either play in coop in your first playthrough if you can manage not failing and controlling two controllers, or if you have someone playing with you. If not then after you beat the game without failing go back and get all the coop trophies.
Just playing through the game you should have aquired most of the other trophies such as "Swallowing 50 enemies with B.O.B." and "Machine Gun Specialist". Which leaves the trophies that will take some time grinding out points/DNA.
Start with the 10 Million Point trophy by following the description for that trophy in this guide. It will take some time grinding points to get this. Then continue going back for the 500,000 DNA trophy. This too will take some time grinding. You can just replay whatever stage you find easiest and that gives a decent amount of DNA each round.
Now all that's left is the DNA Lab trophies and if you have already done the 500,000 DNA then you should have more then enough to go right through this. The only thing that will take a little more time is the Monster Challenge segments in the Lab. If you're stuck getting gold on one particular challenge you can always come back to it after you're done with the rest to get the gold for it.
Then finish up any remaining golds you may have skipped on the Monster Challenges and then enjoy your new platinum.
[PS3T would like to thank Lil_Mermaid_Girl for this Road Map]