Here is the full list of all 15 99 Fails Lite achievements.
Beat all 18 modes
Lartum appeared and then disappeared while you didn’t fail before that event
Black Zeebo appeared and then disappeared while you didn’t fail before that event
Beat 666 pillars for the first time on any difficulty
Beat 99 pillars for the first time on any difficulty
Fail 99 times
Fail 999 times
Fail 9999 times
Beat your own score
Beat friends' scores 99 times
Neebota poked you
Win a run without any fails on record for that difficulty
Collect 999 dopamines
Win a total of 99 times any difficulties!
Get to pillar 50 on 99 pillar mode