Full list of all 20 Tentacles: Enter the Mind achievements worth 200 gamerscore. It takes around 6-8 hours to unlock all of the achievements on Windows.
Achievements they've won
Achievements they've not won
Kill a Rammstein without using any powers.
Crack a black egg.
Equip the rainbow trail and the pink eye.
Reach a multiplier of 10.
Reach a multiplier of 8.
Kill 5 enemies with 1 bomb.
Complete the entire Regret Layer.
Get 5 snipers to aim at you simultaneously.
Use all 3 powers.
Crack a purple egg.
Complete the Libido Layer.
Use a revive token.
Fly through the hole of any knife.
Attach all three tentacles to the oscilator screen on the science box
Have a Kamikaze orbit Lemmy
Pick up 3 tombstones without dying.
Hold on to three rubber duckies at once.
Kill 10 Kamikazes without killing any other creatures.
Crack your first egg.
Go from one pitstop to the next without killing any enemies.