Here is the full list of all 63 Gunslugs achievements.
Chain explosion of 3
Score 2000 points
Get your train ticket and ride.. or run
Complete mission 3.1
Kill 50 guys in one mission
Blow up 4 dudes at once
Score 1000 points
Chain explosion of 2
Complete mission 2.3
Kill 10 guys with grenades
Collect 150 coins
Rescue Willis KiYay
Take a jetpack ride
Locate the arcade !
Rescue Sonya
Kill 20 guys
Rescue Sly Rocko
Find "a" princess
Complete mission 2.2
Drive a tank
Complete mission 2.1
Collect 125 coins in one game
Air kill a dude
Score 500 points
Complete mission 1.3
Kill 5 guys from cover
Change the tune using a jukebox
Blow up 2 dudes at once
Find the voodoo priest
Collect 100 coins
Kill 10 guys in a mission
Complete mission 1.2
Make a chopper crash
Complete mission 1.1
Collect 75 coins
Grab a new weapon
Complete bootcamp
Take cover rookie!
Deactivate your first beacon
Grab energy drink
Complete mission 3.2
Destroy four mechballs
Collect 175 coins in one game
Complete mission 3.3
Rescue B.A. Baracuda
Drive over 5 dudes with a tank
Complete mission 4.1
Drive over 10 dudes with a tank
Rescue Sarge
Score 2500 points
Complete mission 4.2
Blowup a death worm
Complete mission 4.3
Kill a flying fire skull
Complete mission 5.1
Kill 5 skulls in one mission
Complete mission 5.2
Destroy 5 hell tanks in one game
Complete mission 5.3
Complete Hell with Sarge
Complete Hell with BA
Find the sketch world!
Kill a chicken, and spread some eggs!