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