Tentacles: Enter the Mind
20 Achievements
200
6-8h
Down The Knife Hole
Sweet, you found the knife loophole!
10
How to unlock the Down The Knife Hole achievement in Tentacles: Enter the Mind - Definitive Guide
What you want to do is attach all the tentacles to the front of the handle (that is, the side facing the screen closest to you the player, not Lemmy) and then click on the hole so Lemmy's next tentacle takes him through the hole.
On some of the levels within the layers you will see a knife sticking out of the ground with a Lemmy sized hole near the handle. You need to make it about half way through the hole to trigger the achievement. There isn't a really consistent way of doing this. The way I would recommend would be to get close to the hole and tap fast and repeatedly until Lemmy goes through. This might take a few attempts.
On some of the levels within the layers you will see a knife sticking out of the ground with a Lemmy sized hole near the handle. You need to make it about half way through the hole to trigger the achievement. There isn't a really consistent way of doing this. The way I would recommend would be to get close to the hole and click fast and repeatedly until Lemmy goes through. This might take a few attempts.