Grimrock

The marked pit at the right side is not needed to get the secret, but it is needed to get the iron door later on.

North-western puzzle, lock an ogre in the square with the pressure plate to get the secret and a treasure.
Northern puzzle, find the tiny secret button at the end and go back to the space that opens to get the secret.
North-eastern puzzle, push the button (marked to the right on my map) to get the secret.
Western puzzle. Hit and run. The tiny secret button opens that door to the secret not far from where you dropped down.
Eastern puzzle. After teleporting the first time, push the secret button to reveal the secret later on.
South west puzzle. There's a rock in a wall drain that will help you on the way to a secret and the treasure.
South east puzzle. Walk on the correct pressure plates to get out. Stop the blobs as you walk and you'll open a secret room.

There is a secret button that opens the wall that closes. That part is a copy of the ogre "spiral" on level 9 in the original Legend of Grimrock game. You need to find the button and push it before the ogre charges at you and push you too far.