Here is the full list of all 22 Bardbarian achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Do all the things! 100% Completion.
Unlock the mythical 4th party slot.
Post a score in the Day 2 Insane Mode leaderboard. The most exclusive of all leaderboards.
Complete the entire campaign from start to finish without dying.
Complete the "night" chapter.
Fact: There are 1609 meters in a mile.
Complete the "evening" chapter.
Go as fast as you possibly can. (Hint: Upgrade + Song)
Reach 3000m in Escape mode, and he's yours.
Appears randomly in Survival mode. May luck be with you.
Loot 100,000 gold from the corpses of your fallen enemies.
Last for 3 minutes in survival mode.
Play and submit your best time for Survival Mode.
Upgrade a unit to MAX level.
Complete the "noon" chapter.
Waltz into Wave 10 and rescue him from that Fire Golem.
Send 2500 enemies to their grave.
Don't get hit!
You look lonely, have you considered a pet to keep you company?
Complete the "morning" chapter.
Something's cooking on the title screen.
Start a new game in Insane Mode.