How hardcore is hardcore? If you like the idea of recruiting hundreds of Pokemon (including newbies from Diamond and Pearl) to a pool from which to draw your four-mon team, and can handle a flavor of hardcore this friendly and cute, then maybe pick this one up. If you played Shiren, however, you may find Pokemon to be too forgiving for your dungeon-hacking skills.
PROS: Adorable Pokemon dungeon crawling, local and Wi-Fi rescue system
CONS: Top screen feels extraneous, might be too watered down for the hardcore Roguelike set