Here is the full list of all 50 Summer with Mia Season 1 achievements.
Played all the bonus scenes
Acquired all other achievements
Finished the main story
Finished the "farewell" scene
Finished getting leverage on Emma
Finished going to a motel twice
Finished having fun on your couch
Finished Emma's "payback"
Finished Emma getting leverage on you
Finished not getting caught by Mia
Finished visiting a special motel
Finished a perfect late night visit
Finished Mia's third show
Finished Emma's favorite pastime
Finished getting a surprise from Mia
Finished a successful massage
Tried the cereal last
Used the Panic button once
Finished Mia's second show
Finished getting tricked by Mia and Emma
Finished shooting your first short film
Finished a late night visit for the second time
Finished a certain late night visit
Finished helping Mia with clothes shopping again
Finished Mia's first show
Finished spying while getting distracted
Successfully "killed a spider"
Survived Mia's revenge
Finished getting Sam to help you with Mia
Finished helping Mia try on some clothes
Finished getting through the storm
Finished some much needed assistance
Finished playing truth or dare at Sam and Emma's
Finished the barbeque
Finished a quickie with Mia
Finished helping someone go to bed
Finished your first time with Mia
Decided on all the relationships
Chose to play without NTR when the game started
Chose to play with NTR when the game started
Got to the bathroom before Mia put the towel on
Finished the photoshoot with Mia
Finished spying on Mia in the bathroom
Finished watching Mia do yoga
Finished tricking Nathan to help you with Mia
Finished playing blackjack with Mia
Finished Mia's attempt to tease
Chose correctly when talking to Tatjana
Finished watching Mia change
Didn't miss the password for Mia's laptop