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