Very different game, to its credit. Makes you wonder why this type of game isn't more common. Very, very deep story.
The biggest downside to this game is the load times. Seriously, about 10-15% of my game time was spent loading. Compared to games like Zone of Enders 2, which runs as fast as any game I've ever seen, the programmers on killer7 appear to not know how to maximize the possibilities of the PS2. This isn't a game I will likely play many times, since the puzzle element to the game is no longer interesting on subsequent replays, but the bosses in the game, and a few of the elements such as Susie, and the storyline are wonderful.
Many elements in the game for some reason remind me of David Lynch movies like Blue Velvet and Lost Highway.
This game can be had for ~5$ online, and for that price it's well worth it.