Quitter
Anytime during the game, either select the gear in the upper right corner or hit the Escape key to open the menu. Select Quit to quit the game. You'll achieve Quitter.

Returned
Obtain the Quitter achievement, then start the game again. You'll automatically achieve Returned.

Egg Sequence #1
Complete the first test. When asked if you'd like to take the Bonus Test, select Yes. When asked if you want to get stronger, answer No. When asked why are you here, answer with I wanted to see what you would say. When asked if you like to provoke people, answer Yes. When prompted to ask a question, select What is your mother's maiden name? You'll achieve Egg Sequence #1.

Egg Sequence #2
Complete the first test. When asked if you'd like to take the Bonus Test, select Yes. Answer the first question (about how many bones are in a new born baby) with 305. Answer the second question (0,1,1,2,) with 3. When asked if you think you're smart, select Yes. Answer the first question (a list of numbers) with You. Answer the second question ("Yes.") with Mean. Answer the third question ("Next one.") with Nothing. You'll achieve Egg Sequence #2.