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