Here is the full list of all 16 DragonScales 5: The Frozen Tomb achievements.
Collect 100 scales
Collect 1000 scales
Collect 5000 scales
Get 10% of stars
Get 50% of stars
Get ALL the stars
10% of best times
50% of best times
100% of best times
10,000 score points
100,000 score points
500,000 score points
100 cascades
Remove 100 skulls
All levels completed
50 power cards used