Here is the full list of all 23 Mirrors achievements.
Complete all 5 stages with at least one Canopic Jar per tomb.
Complete Stage 1.
Complete Stage 2.
Complete Stage 3.
Complete Stage 4.
Complete Stage 5.
Create a level using the Level Creator.
Create 5 levels using the Level Creator.
Successfully complete 100 tombs.
Successfully complete 250 tombs.
Complete a level by surpassing all requirements.
Take a look at the Journal.
Prove that you're faster than a Mummy.
Complete a level while a Mirror is frozen.
Complete a level while a Mirror is wrapped.
Get to the 10th tomb in Time Attack.
Get to the 20th tomb in Time Attack.
Get to the 30th tomb in Time Attack.
Complete a tomb in Time Attack with 1 second to spare.
Destroy a Mummy.
Squash a Scarab.
Squash 10 Scarabs.
Squash 50 Scarabs.