This is my favorite first-person RPG, and the only first-person RPG I've played so far (I know, I still need to experience other first-person RPGs, like Dungeon Master, Advanced Dungeons & Dragons: Eye of the Beholder, and Obitus). I absolutely love this game. Sure, it's got its issues, but even so, I find myself enjoying it very much. Plus, the soundtrack is spectacular, and I like how the game automatically maps itself, so the chances to get lost would be low.
This is also the first game that Kirby appeared in, during a brief portion of the intro.