Etrian Odyssey is a first person dungeon crawler. Where you have to use the bottom screen on the 3DS to draw in your map as you progress through the maze like levels. And each level is filled with random battles, and larger , more dangerous monsters who roam the maps waiting to kill you, and bosses. If you are prepared to put in the time and effort, this game is very rewarding and can take a very long time to complete. You can select from a bunch of characters to form your party, all with different abilities. You name them, level them up and give them new armor, weapons, skills and so on. Etrian Odyssey is all about exploring the levels step by step, and marking out your path on your map as you go and learning the best tactics to beating the monsters.
My advice is to try out the demo on the Nintendo eshop before you purchase this game if you are new to the series, because it's a large demo that lets you sample a good chunk of gameplay. some will like it, and some will not ,the map drawing and and the sometimes hard battles will turn some people off . For others, this is a highlight of the game. These types of games are pretty hardcore, But if you give it a try, and don't give up when your party gets wiped out by something like a angry bear, you will find a very rewarding and enjoyable game that will have you hooked for many many hours.