Here is the full list of all 18 Squidlit achievements.
Find Riverjack!
Hug Skwit Skwot!
Restart the Game!
Don't get inked during the credits!
Make the music stop!
Continue to ink after beating the sharkerfly!
Feed all of your muffins to Skwit Skwot!
Become a squidlit repellant connoisseur!
Continue to wiggle on the final screen!
Complete the game without stress eating a muffin!
Don't let Grimwar summon anything!
Don't start the game for a minute and a half!
Beat the sharkerfly in less than 5 seconds
Beat the game in less than 12 minutes.
Beat the game in less than 11 minutes
Beat the game in less than 10 minutes 30 seconds
Beat the game in less than 10 minutes (Wow!!!)
Wiggle at all the squidlits!