Here is the full list of all 18 Riddled Corpses EX trophies - there are 5 bronze, 2 silver, 10 gold and 1 platinum.
Unlock all trophies in Riddled Corpses EX
Complete arcade mode
Upgrade at least 4 characters to max level
Unlock all the characters
Complete stage 6 in story mode
Complete stage 5 in story mode
Complete stage 4 in story mode without using any special item
Unlock the turrets
Complete stage 4 in story mode
Survive through 5 waves in survival mode
Unlock the MK 1000
Complete stage 3 in story mode
Complete stage 2 in story mode
Get at least one of each collectible item
Electrify 30 enemies during the same run
Complete stage 1 in story mode
Burn 100 enemies during the same run
Die in any mode