Did somebody mention...Lord Gek?
Even though I still don't know a word of Japanese this game held me rapt for months!
As far as what the Shiren series in general is like I'd say it's closest comparison might be Hack (so more to it than Rogue but not quite up to the complexity of Nethack) but in it's own Japanese folk inspired mythos. There are no classes, the only personal stats are strength and hit points, and your character has no actual skills other than what his items allow him to do (so proper management of your wands, weapons, armor, rings, scrolls, etc. are key to your survival in the game). In an attempt to compromise between the traditional Roguelike's harsh one life and then you must start over from scratch, Shiren the Wanderer as well as the other games in this series traditionally had it so your character lost all of the equipment he had with him when he died and (depending on which Mystery Dungeon game you played) sometimes would reset his level back to 1 forcing you to practically start from scratch. To at least give your future runs a little bit of a leg up your character is free to store away items back in town at various points in the game for use on later runs. Therefore a big mechanic of these Mystery Dungeon games became knowing what to keep with you and what to store away for later. Store away all of your best equipment and you'll doom your current run...but at the same time if you only store the really useless crap you aren't helping yourself much in future runs. Another key aspect in the Mystery Dungeon games is that a lot of the creatures will "screw" with your inventory (something that seems so taboo in most RPGs). There are beasts that will steal from you, rust your equipment, outright destroy it, or even turn a random inventory items into a food ration (is that a good or bad thing...it all depends).
Shiren 3 for the Wii is a really high production roguelike (lots of story related cutscenes and boss fights) that actually tries to take many steps to bring newcomers into the traditionally harsh world of the Shiren series.
-Your characters have persistent levels (so you never have to start from scratch again in the main story quest).
-As opposed to one long epic dungeon the game is divided into many small 5-12 level dungeons for the most part so even if you do get killed you'll never have to backtrack that far.
- There is even an option to remove the traditional, "lose all of your carried items when defeated" aspect of the game.
-They even managed to push many of the most annoying inventory screwing creatures out of the game's main story (only to mess with you in the many very brutal post story dungeons).
-So while this game is still much more about careful item management than say Pokemon Mystery Dungeon which was more about using your characters' special abilities to make it through the game's challenges, this game's flow and difficulty is much closer to the Pokemon Mystery Dungeon game than any of the previous Shiren games.
So while I myself actually felt many of these changes were for the worse compared to the previous Shiren games, I think the developers had cleverly proven that they hadn't forgotten us hardcore Shiren fanbase. Once the game's final big story quest boss fight is completed a number of much tougher post story dungeons are unlocked that add even more advanced baddies, gameplay mechanics, and other fun surprises. So for those who just want a good story driven quest that never really gets too frustrating or annoying, there is the main story but for those who want to really test their mettle, just slog through the story and you will be richly rewarded.
Let me know if I can answer anything more specifically about the game as I did complete at least the main story aspect and at least unlocked all of the additional dungeons (but completed very few) I'm pretty knowledgeable about this game with one HUGE exception. Not speaking or reading Japanese I only have a very vague and hazy understanding of the game's plot and storyline which, as it takes some pretty wild twists and turns, wasn't that easy to follow just by watching the zillion cutscenes ("Wait, why is Shiren now fighting THAT GUY of all people?").
