It’s behind the toilet.
Izuna is really good, in my opinion.
It’s a hardcore rogue-like. No save points, only save and continue later. If you die, you lose all your money and equipment… but retain your experience and level.
There is tons of loot, a lot of it really fun to use (dropping caltrops behind you, throwing stars, etc). It plays exactly like Rogue as well, with prettier graphics and a better interface. It’s also kind of funny to boot.
I liked it a lot more than Pokemon Mystery Dungeon, which is very similar.
How much replay does Izuna offer?
First of all, Izuna is a roguelike game, so all the dungeons are the same random-generated dungeon. You might choose to go down different dungeons (one corresponding to each god in the game), but the only difference between them are the level of the enemies.
Also, I would say that the replay value comes from not finishing the game, but continually running dungeons to gain stuff to improve your weapons.
I’ve read from the faq that there is a real rogue game unlocked after you finish the story. Meaning that you start at level 1 again with no weapons, and must stay in the dungeon until you’re at the bottom.