I struggled a little in the beginning with the controls because I have a junky mouse (also, keep in mind that not everyone has a middle mouse button!) but then was able to play properly. Is there a reason you didn't just use keyboard movement (up/down for forwards/backwards and left/right for rotating the camera)?
The game has an interesting premise but, like @sMashZa, I guessed the correct answer based mainly on the last letter and don't feel that the other letters really gave too many clues, they just deepened the mystery. I feel that the game needed a few more clues and objects to interact with but I presume you did what you could with the time constraint. I quite liked the floaty visual style of each room being a separate block.