Alphabet from the game "Fez". Both variants: Big letters are directly from the wiki here: http://fez-game.wikia.com/wiki/Zu_Alphabet and are "uneven", with some not square elements. That's how they appear in the dialogue. Small letters are perfect square. That's how they look in inscriptions. The letters are written vertically top right to bottom left ingame. Space is spaced for small letters. Numbers are also included. Additions are indicated with numbers "overlapping" without a space (see here http://www.xblafans.com/wp-content/uploads//2012/04/Number-System-Solution.png) Plus some extra symbols like the key codes.