Mushroom Wars

Unfortunately, you actually need two controllers for this trophy (the game pops an error if you just try to change controller ports). This can actually be done fairly quickly by yourself. Just select 'Duplex I' and set the game type to 'domination'. You will have more than enough men to take all three of the required buildings in one wave, which takes about 20 secs. Rinse and repeat until you earn the trophy but you can also see how many games you've played from the main menu.