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