Here is the full list of all 48 Dead Island achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Complete act 1 with 4 different characters.
Play in a co-op team of 4 different playable characters.
Complete 5 quests with 3 co-op partners.
Kill a Ram using tackle skill.
Kill 5 Infected in a row with a single blow.
Kill 150 enemies using Analog Fighting controls.
Reach level 50
Kill an Infected with a grenade blast.
Set 10 zombies on fire simultaneously.
Heal yourself with a medkit 100 times.
Kill a Suicider with a grenade.
Customize 25 weapons
Kill 10 zombies in a row with headshots.
Complete act 4.
Kill 250 zombies using firearms.
Explore the entire island.
Complete act 3.
Loot 25 Exceptional Weapons.
Use a large medkit to heal an injury of 5% or less.
Find 120 collectibles.
Kill a Butcher using an axe
Complete act 2.
Kill 100 enemies with Fury attacks.
Drive a total distance of 10 kilometers.
Kill 250 zombies using edged melee weapons.
Kill 250 zombies with modified weapons.
Finish 75 quests cumulatively.
Use a hammer to kill a series of 15 zombies without taking damage.
Kill 50 human enemies.
Play Dead Island at least 28 days after starting it for the first time.
Kill 250 zombies using blunt melee weapons.
Save 5 people besieged by zombies.
Sever 100 limbs.
Reach level 25.
Travel a distance of 20 kilometers on foot.
Find 60 collectibles.
Create weapons to rival the gods of fire or thunder.
Join another player's game.
Kill 25 zombies with your bare fists.
Complete act 1.
Create a customized weapon.
Kill 50 zombies using a vehicle.
Complete 25 quests while playing with at least one co-op partner.
Kill a zombie with 10 different melee weapons.
Reach level 10.
Breach a locked door with the first blow.
Complete 5 quests in a single co-op game with the same partners.
Play with 10 different co-op partners for at least 15 minutes each.