These images clearly show how to get 80Gs
I will the first person to admit that I had my issues with Dead Rising 2, but despite the dodgy save function and the constant loading, the game was still fun when played in co-op. There are surprisingly few co-op specific achievements available in the game, but this should not stop you working together to get some of the others.
Dead Rising 2 is as about as generous as Scrooge, pre-three ghosts, when it comes to basic achievements for simply playing the game. If you complete the original days, successfully achieve all the tasks and tackle the final overtime you will get the mind blowing amount of 40Gs. That is a lot of work for little reward. To compound the issue you should get a further 20Gs for completing the game with a co-op pal, but this will need to be done in one massive session as the constant saving and kicking means the game suspects you have not played co-op throughout. Getting 60Gs for completing the game in co-op will be no easy task!
Maskerade – 20G
After the frustration of trying to get the story based achievements the game really shines when you stuff the narrative and have some co-op fun. One achievement that is easier as a twosome is ‘Maskerade’ which requires you to place 10 masks on 10 separate zombies at once.
After you both exit the safe house into the Mall area head left to a large open space with escalators leading up. Stop! Rather than head up the stairs, go into the toy shop hidden behind one of the escalators. Just inside the door is a box full of an infinite number of dinosaur masks. Both of you can go mask crazy putting as many of the Dino Visages on the undead horde. It’s so much easier in co-op because on your own you can easily find yourself surrounded by the living dead and being killed before you can cover 10 zombies.