Here is the full list of all 20 Bard Idle achievements.
Reach zone 50
Reach zone 45
Reach zone 40
Reach zone 35
Reach zone 30
Reach zone 25
Reach zone 20
Reach zone 15
Reach zone 10
Reach zone 5
Reach zone 55
Reach zone 60
Reach zone 65
Reach zone 70
Reach zone 75
Reach zone 80
Reach zone 85
Reach zone 90
Reach zone 95
Reach zone 100