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