The In the Dark Add-on for Lil Gator Game has 19 achievements.
Gain access to the underground.
Complete Amberly's quest.
Complete Ruth's quest.
Complete Emilio's quest.
Complete the story of In The Dark.
Beat Ruth's minigame while she's paying attention.
Defeat Amberly in a fair-enough race.
Get 5 unique endings to Emilio's movie.
Break everything in the underground.
Make friends with everyone in the underground.
Craft every item in the underground.
Get your first charm item.
Get one of each type of charm weapon.
Get all charm items.
Complete Nodd's research.
Clean up all the rubble in the underground.
Discover a secret passageway between the island and the underground.
Use the web shield. Yep, that's what it does.
Catch up with your surface friends hanging out near waterfalls.