Number of achievements: 46
Number of missable achievements: 4(?), difficult to assess due to bugs
Minimum Playthroughs: 1
Free-Roam After Story: No, chapter select available
Does difficulty affect achievements?: No

All missed achievements can be earned using Chapter Select menu.

Since almost all achievements can't be missed I've decided to list only those which are missable.

Note. At the time of creating this guide there seems to be a bug related to achievements requiring multiple actions e.g. "Solve 3 mindmaps" or "Wear 3 costumes" or "Make 5 matches". If you make some progress towards them but then exit the game their counter will be back to 0 when you launch the game again.

Cabinet of curiosities
Inspect all curios in The Legend of Arsène Lupin


Inspect all exhibits in the museum:

1. Portrait
   
2. Bejewelled necklace
   
3. Chest of jewels
   
4. Inspect Diamond necklace.
   
5. Inspect Motorcar.
   
6. Inspect Stone statue.
   
7. Inspect Gaudy necklace.
   
8. T-Rex skull
   
9. Faberge Egg
   
10. Black pearl

Nelly Underdown
Impress Nelly Underdown


The next day after having dinner with Miss Underdown you can go to the Storage Room and pick up a white rose. Give it to Miss Underdown.



Horace Velmont
Uncover a secret about Horace Velmont


During the final dialogue with Miss Underwood select these answers:

1. I wanted to show you I'm a man of my word.
   
2. No.

The real Lupin?
Reveal the 'real' Lupin in A Chance Meeting


During the final dialogue with Miss Underwood select these answers (continuing from the previous achievement):

1. I think you already know...
   
2. It's all I've ever known.
   
3. I'm sorry