Since there is no in-game map, I have mapped it out as follows. The purple stars represent useful items like keys. Red doors can't be opened. 2f is accessible from either the double pink doors in the main 1f hallway (after unlocking from the other side) or via the Hagith elevator. The double pink doors sort of warp you to the second floor, like the Alternate Midwich bathroom does. Door solutions are on the 3f map.
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In the video, I walk through the whole level with no fighting and with overlaid highlighted maps to show the layout and how the warp door works.
Below is a diagram of how to move from one map to the next via stairs, elevator, or pink warp door.
Speed Guide
Basement-get pliers and screwdriver.
Bathroom-use screwdriver on pipe to get Key of Ophiel
use on Ophiel door in main hall
Second door has the Zodiac puzzle. Get the stone of time
use ALERT code on door, get amulet from the morgue (2nd door)
Back to the main hall, enter the antique shop door
Use stone on clock to get the Hagith key
go through Hagith door and take elevator to 3f
solve door keypad puzzles to get the bird cage key
use elevator to go to 2f
go to jewelry shop door for Crest of Mercury and Ring of Contract
back to the hall, go through the other double brown doors and then straight ahead to get back to main hall
use bird cage key on bird cage room to get key of Phaleg
the next door over is the Phaleg door, which takes you to a hall with 6 doors inside
go to the kitchen and use the Ring of Contract to fix the chain, THEN get the Dagger of Melchior (not before, unless you've just saved!)
enter storage room, open jelly beans to get Bethor key
if you want to use the VCR, it's in the other door in the storage room
use the Bethor key to turn off the generator
back to main hall, go through pink double doors to get to the aratron/electric key room on 2F
back through pink doors to 1f, then through phaleg door, use aratron key to see cutscene, pick up Disk of Ouroboros
go to the graffiti room to get the ankh
use all 5 items on the final door in Alessa's room, enter, go downstairs for final boss area
