Just spam "E" or whichever keybind you set to be your action button.

I achieved this in the "Windmill" level where everything is burning and you are dragging yourself on the ground. The game continuously asks you to press E at certain points. That is where my achievement activated.

In the room where you first start the game is a photograph of an anime girl on the wall. Just go up to the wall and stand there for about 10 seconds. I also took a screenshot and hit E while I was there, but achievement was activated after standing there... (not sure if it was a combination of the above or if you just have to stand and look at the photo up close).

When you are in the "Parlor" room, just crouch down and go into the fireplace and the achievement should activate.

In the level "White Pawn" turn on the radio on the couch. Vinny yells for you to name something sweet. Just type in "honey".

(See achievement One Day for another achievement in this room before you turn on radio)

In the level "House", just head to the basement. You will come upon a room with candles on the floor and a picture with the quote by Albert Einstein. Just hit the lever button continuously until the achievement pops up.

In the level "Immensity", jump from pillar to pillar while shooting and breaking the green vases. Once you break enough, a huge green vase will fall from the sky and award you with this achievement.

At first the achievement did not pop for me in my attempts for it. I ended up falling and spawning on the lower pillar, shooting it again and one found on a nearby ledge which then activated my achievement.

I made this video below to help you out.

Complete the Black Pawn Scenario. Level name is "basementpart2".

Once you get out of the house, you chase the orb back through a door. When you break through that door, your achievement should activate.

If it doesn't, I suggest exiting your game and verifying your cache.
Game Library > Only If > right click Properties > Local Files > Verify Integrity Of Game Cache (last button).

If that says something with failed to verify 1 file. Verify again until it's successful, then try that level once more so achievement will pop up.

Complete the White Pawn Scenario. Level name is "whatithinkofyou". (See below "Quality" achievement for quick way out of this room.)

Complete the last level with a single bullet. Level name is "whatithinkofyou".
You are in a room full of green vases. Head north from where you spawn until you spot a trashcan. Press E. Grab the key. Now head south until you see the tipped over green vase. Shoot it ONCE. Go into the door. You will unlock the Quality & Wincest! achievements here.

In the level "White Pawn", jump onto the desk before talking to radio. Turn to the shelf that you once got that gold key from in earlier levels. Run and jump off the desk onto the top of this shelf. Turn slightly around and the ceiling will cross with the outside sky revealing a giant anime photo.

Note: Exit and reload your game if you don't get it the first time as this is what happened for me.

Thank you J'adore l'alcool & Raptor for input for this secret achievement.

I added a video on how to achieve this below.

• A few achievements were removed by the developer temporarily (including Ribbit). If and when they are put back in, they will be added to the guide.
  
• Most of these achievements can easily be obtained by loading up the level name.
  
• If any achievements don't show up, try to "verify game cache" from your game library before trying again.