For old-school masochists. Others need not apply.
Etrian Odyssey is not for everyone. In fact, Etrian Odyssey is probably for very few people. It's a decidedly niche title, and if you have either outgrown "old-school" role-playing mechanics or are expecting a cinematic experience on the level of today's Japanese role-playing adventures, this game will disappoint you.
That said, Etrian Odyssey will very likely greatly satisfy anyone in its target market. The mapmaking tools are there for anyone who fondly recalls drawing their own maps for their adventures (Metroid comes to mind), and the character customization system is surprisingly robust, with each character class boasting anywhere from ten to twenty different upgradeable skills. It's incredibly difficult, too, which should satisfy anyone who's waded knee-deep into dungeon crawlers and roguelikes and lived to tell about it.
Further, there's a host of different enemies to battle, pickups to collect, items to craft, and sidequests to take. The artwork is splendid too, and though most of it consists of static drawings, the overall visual experience is quite nice. The dungeons are rendered in 3D with polygons, and of course the Nintendo DS can't boast the graphical prowess of today's higher-end systems or even the PSP, but the 3D still runs smoothly with enough detail to not make it look like a mess.
The gameplay largely consists of going into the dungeon, exploring it, fighting enemies in a turn-based battle system reminiscent of older Dragon Quests, with a variety of weapons and magic spells. You will hop back to town frequently to heal up and replenish used items, sometimes supplying the weaponsmith with items needed for new weapons, and then delve right back in to venture deeper into the dungeon.
With regards to its intentions, then, Etrian Odyssey succeeds on every level. The only issue is the limited market appeal this game will have; not that it's a knock on the game itself, but unless you -- dear player -- fit the criteria, you should likely avoid this game. Etrian Odyssey is great at what it sets out to do, and what it sets out to do is admirable and entertaining, but it's also only for a select few people.