Undertale secret rooms

More info on: 0:00 room_gaster 0:39 room2 0:41 TESTROOM 1:02 room_water_redacted 1:15 room_water13 1:31 room_overworld 1:43 bullettest 1:50 room_spritecheck 3:14 room_joyconfig 3:26 room_controltest 3:44 room_fire4 4:02 room_fire10_old and room_fire10A_old 4:31 room_tundra_placeholder 4:56 room_ruins_12B_old 5:13 room_tundra_rollsnow 5:36 room_water7_older 6:11 room_meetundyne_old 7:49 room_water_mushroom 8:41 room_monsteralign_test