Let's replace the letters and align the words! A new sense of crossword puzzle that makes the pleasure of filling become a habit. If you know the words that enter each square from the vertical and horizontal hints, replace the letters! "Irekae IQ Crossword DX" is a crossword puzzle you play by replacing panels. If multiple words are completed with a single replacement, you will get a high score! In addition, the player's IQ level is judged according to the time required to clear and the score. There are three types of game modes: "World Mode" that clears the stage within the time limit, "IQ Test Mode" that determines the player's IQ level, and "Free Mode" that solves problems without worrying about the time limit. You can participate in each national ranking with your score and IQ index.