Attack on Titan is an RPG game being developed by GameDreamer. This game allows you to create your own character in the Attack on Titan universe.
Once you start up Attack on Titan, you'll be prompted to create your own character. From there, you can explore and take on missions with various characters from Attack on Titan. The missions in the game will take you into combat in which you'll have to tap on your screen at the correct time like if you were playing a rhythm game.
Overall, Attack on Titan is a great RPG game if you're interested in the Attack on Titan franchise but it can be very confusing if you haven't been introduced to the property before.