Here is the full list of all 57 Kill to Collect achievements.
Kill 4 or more with one rocket using the Rocket Launcher.
Kill an enemy in a factory shredder.
Kill 15 enemies with a Flamethrower.
Complete a "One Try" Challenge.
Complete a Repeatable Challenge
Kill an enemy with the last bounce of the laser disc.
Kill 3 enemies with one use of Ironfists ultimate ability.
Revive a friend with less than 1sec left on the timer.
Hookshot 15 enemies.
Strangle someone to death with the LazerWhip
Complete a floor using just x -attack (Dodge is still allowed)
Set fire to 3 enemies with one Incendiary Grenade.
Gib one of every enemy in the game.
Complete a (not challenge, not tutorial) bounty in 350s or less.
Complete a floor ( not tutorial ) in 90s or less.
Hit 5 or more enemies at once with Kate Katanas Crackdown.
Have an Artillerist die by his own grenades.
Land 50 consecutive attacks in a row without taking damage.
Land 20 consecutive attacks in a row without taking damage.
Clear every challenge room in a bounty without dying.
Beat a Challenge Room without taking any damage.
Kill three enemies in one bull rush.
Deploy 4 turrets in a fight
Blow 3 enemies up with a Grenade.
Kill 3 enemies with one Proximity Mine.
Kill 8 enemies with one Lazer Cutter.
Kill a Defender with the Handcannon
Complete the campaign as Kate Katana.
Complete the campaign as Ivan Ironfist.
Complete the campaign as Riot Ray.
Complete the campaign as Shocking Shelly.
Watch yourself being placed first on a leaderboard.
Kill a Vanguard with a whip
Kill a friend with the Rocketlauncher
Have your turret kill a Bounty Target.
Complete all chapters of the campaign in any way you like.
Complete the campaign with Kate Katana on Hard difficulty.
Complete the campaign with Shocking Shelly on Hard difficulty.
Complete the campaign with Ivan Ironfist on Hard difficulty.
Complete the campaign with Riot Ray on Hard difficulty.