The Collector's Puzzles

Exploration Stage: City Hall
From: Martha
Description: I looked through lots of tomes in City Hall. The game machine is an invention of the Collector, the researcher of the City's secrets. The notes say that along with the machine, the Collector created puzzles that bestow special abilities on anyone who manages to solve them. I really want to get my hands on the Collector's puzzles. Judging by the notes, you can get them from the game machine. Help me get the first puzzle - the "Collector's Cube".
Completed: What a wonderful puzzle! It's an ordinary Rubik's Cube, but there are letters and symbols on each square. If you run into a dead end, use a hint. After assembling the cube, you'll be able to read the phrase. The puzzle will be very useful for an explorer of caves and tunnels.