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.
Send 2500 enemies to their grave.
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.
Complete the entire campaign from start to finish without dying.
Complete the "evening" chapter.
Loot 100,000 gold from the corpses of your fallen enemies.
Fact: There are 1609 meters in a mile.
Complete the "noon" chapter.
Waltz into Wave 10 and rescue him from that Fire Golem.
Appears randomly in Survival mode. May luck be with you.
You look lonely, have you considered a pet to keep you company?
Upgrade a unit to MAX level.
Something's cooking on the title screen.
Start a new game in Insane Mode.
Play and submit your best time for Survival Mode.
Last for 3 minutes in survival mode.
Reach 3000m in Escape mode, and he's yours.
Complete the "morning" chapter.
Don't get hit!