Get the Shark Costume from Joe, then go right into the break room. There are some Biologists here. Afterwards, go to every Biologist in the large room that leads into the cafeteria.
Easy "Head Otter" achievement
In the "World of Kelp" level. stop the Kelps that your sons shoot at you with an otter figure. After that mini-game ends, pick up the otter's head and put it on your head.
Easy "Number 100 Dad" achievement
At the start of the last chapter, "Hot Concessions", allow the game to idle until you die one hundred times.
Easy "Oh Captain, My Captain" achievement
Get the captain's uniform, then return to the ship and approach every sailor. Make sure they talk to you and not with each other. You also have to talk to the sailor who you stole the coffee from after going back over the beam crane.
Easy "Secrets of the Deep" achievement
Play "Deep Dark Sea". After you get the shake light, Stacy will ask for it when you find the biologist. Before giving her the shake light, continue walking ahead to find the jellyfish collection.
Easy "Stay True to Yourself" achievement
Play under the easy difficulty setting in order to have no consequences if you get seen by Biologists. After leaving the Gift Shop, enter the Ladies toilet. Go through the gutter into the break room, start the fire, the exit through the Men's toilet and walk through the turnstile. Do not take Joe's Shark Costume. Just go to the Cafeteria and enter it through the service hatch.
Easy "Trim Your Moustache" achievement
Throw the birdhouse back onto the hook. Simply placing it there will not work.
Easy "Unacceptable Purchase!" achievement
After escaping the Chef in the "Supermarket" level, take a lemon from the fruit department and scan it at the checkout.
Free Play mode
Successfully complete the game.
Minecraft reference
You can find a display for the "Mintcraft" game inside the grocery store.
Secret level
Start a non-Free Play mode game. Sneak past the scientists through the gift shop in the Aquatic Fun Center. Enter the men's bathroom. Enter the center stall on the left, sit on the toilet, and flush it.
The Stanley Parable reference
There is a poster for "Stanley's Pair o' Bowls" featuring a blue suit and red tie, referring to the game The Stanley Parable.
