Here is the full list of all 24 Bard's Gold achievements.
Die 50 times
Ran out of time
Defeat 250 enemies
Unlock 20 chests
Clear the first world
Find a bonus level
Find 100 or more secrets
Level up a skill
Collect 1000 Gems in a single run
Discover tower of patience
Find a hidden treasure
Find a skill book
Defeat the Blood Ghost
Find the secret discount
Make a deal with Reaper
Collect total of 50000 Gems
Clear the second world
Clear the third world
Complete the game in any difficulty
Sell your soul to the Reaper
Break 200 vases
Kill the creep of shadows
Clear a world without losing a single life
Find all skill books