Here is the full list of all 35 Disc Room achievements.
DEFEAT THE ULTIMATE GATEKEEPER USING EVERY ABILITY
EXPLORE ALL ???? ROOMS
SURVIVE 20 SECONDS IN EVERY ROOM
HOLD DOWN FFW FOR 10 SECONDS STRAIGHT
UNCOVER THE GOLDEN MYSTERY
SURVIVE 10 SECONDS IN EVERY HARD ROOM
EXPLORE ALL HARD ROOMS
SURVIVE 20 SECONDS IN EVERY ROOM IN ONE ZONE
EXPLORE ALL ROOMS
DIE FROM ALL DISCS
DISCOVER THE FOURTH GOLDEN ROOM
QUIT TO MAIN MENU WITHIN 2 SECONDS AFTER DYING
DIE FROM 4 DIFFERENT DISCS IN ONE LIFE
FOLLOW THE PATH
UNLOCK ALL 6 ABILITIES
DIE FROM ALL DISCS IN ONE ZONE
SURVIVE 0 SECONDS OR LESS
COMPLETE HARD MODE
WALK 10K STEPS
END A RUN FROM THE MAP
SURVIVE 20 SECONDS IN ANY HARD ROOM
START HARD MODE
DEFEAT THE ULTIMATE GATEKEEPER
DISCOVER THE FIRST GOLDEN ROOM
DISCOVER THE THIRD GOLDEN ROOM
???? THE ????
DEFEAT THE PHANTOM GATEKEEPER
DISCOVER THE SECOND GOLDEN ROOM
SURVIVE 60 SECONDS IN ANY ROOM
DEFEAT THE CARNIVOROUS GATEKEEPER
FACE THE GOLDEN CARCASS
FEED ???? 4 ????
DEFEAT AND REVIVE AN ANTIBODY
DEFEAT THE OVERGROWN GATEKEEPER
DEFEAT THE ARMORED GATEKEEPER