Here is the full list of all 12 At Your Feet achievements.
Unlock Natalie's Teacher Ending
Unlock Lucy's Conformist Ending
Unlock Victoria's Athletic Ending
Unlock Lucy's Maverick Ending
Unlock Lucy's Truth Or Dare CG
Unlock Melanie's CG
Unlock Victoria's College Ending
Unlock both Victoria's endings with a score of 100
Unlock both Lucy's endings with a score of 100
Unlock Natalie's Revenge Piano CG
Unlock Natalie's Pianist Ending
Unlock both Natalie's endings with a score of 100