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