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