Here is the full list of all 13 Dead Island Retro Revenge achievements worth 1,000 gamerscore.
Complete Marathon mode
Attain 5 stars on all story stages
Reach Stage 2-5 in Marathon Mode
Reach wave 10 in Survivor Mode
Reach a combo of 99 kills in any mode
Finish a stage without ever changing lanes
Finish a stage without killing a single enemy
Complete the final stage and story mode
Kill 10 enemies with one sledgehammer power-up
Finish a stage with the crosshair off
Finish a stage without taking any damage
Get 20 projectile kills in a single stage
Complete your first level