Here is the full list of all 40 Super Kill-BOI 9000 achievements.
Start a round in the Wastelands
Win a round in the Wastelands in Normal mode
Win a round in the Wastelands in Hard mode
Start a round in the Jungle
Win a round in the Jungle in Normal mode
Win a round in the Jungle in Hard mode
Start a round on the Moon
Win a round on the Moon in Normal mode
Win a round on the Moon in Hard mode
Unlock Hard mode
Donate 1000 hearts to Kill-BOI
Donate 10000 hearts to Kill-BOI
Find a Katana
Kill 1000 enemies with a Katana
Kill 1000 enemies with your stick
Kill 2000 Creepers
Kill 20000 Creepers
Kill 1000 Exploders
Kill 10000 Exploders
Kill 1000 "Birds"
Kill 10000 "Birds"
Kill 100,000 "Things"
Reach 11 minutes in Endless mode
Reach 15 minutes in Endless mode
Win 10 rounds
Pick all Drone upgrades in the same round
Pick all Flame Thrower upgrades in the same round
Pick all Gun upgrades in the same round
Pick all Blastinator upgrades in the same round
Pick all Pumpkin upgrades in the same round
Pick all Saw upgrades in the same round
Pick all Cannon upgrades in the same round
Pick all Black Hole upgrades in the same round
Pick all Beam of Friendship upgrades in the same round
Pick all Grenade upgrades in the same round
Pick all Snowball upgrades in the same round
Fill all inventory slots
Find a Legendary item
Have all items at least Epic
Have all items Legendary