Here is the full list of all 40 Indie Game Battle achievements.
Play a match in Turbo Mode.
Win a match as The Kid.
Win a match as Poncho.
Win a match as Max & STEVE.
Win a match as Bingo.
Win a match as NoLegs.
Win a match as Zee Tee.
Win a match as Captain Viridian.
Win a match as Goat.
Win a match as Teslakid.
Win a match as Adventure Pals.
Win a match as Salad Fingers.
Win a match as Jarvis.
Win a match as Artist.
Win a match as Gontaper.
Win a match as Electroman.
Win a match as Rex.
Win a match as Gip.
Win a match as Sol.
Win a match as Cal.
Win a match as Huey.
Get 10 total KOs!
Win a match as Chip.
Win a match as Aria.
Win a match as Matt.
Win a match as Wizard.
Win a match as Woodle Tree.
Win a match as Red Drop.
Win a match as Pico.
Win a match as Blue Blob.
Win your first Survival match.
Win a match as Dust.
Launch the game for the first time.
Get 100 total KOs.
Get 500 total KOs.
Get 1000 total KOs.
Get 5000 total KOs.
Get 10000 total KOs.
Get 50000 total KOs.
Get 99999 total KOs. Wow, you deserve a cookie for this one.