The most outrageous game I've ever played
OK, let's talk about graphics. This game looks and feels really good, it's like playing an anime. Graphics are very stylized and are really nice to look at them. All characters have a unique look and the Heaven Smiles are very varied. The game also incorporates, in addition to the real-time cinemas, some really cool anime-style FMV's, which look really good. The weak point in the graphics department is that I think this could have looked better; the style is good but textures could have been a little more refined, some shadows look kind of weird and the game has kind of a lo-res feel... The Wind Waker feels like a sharper game in graphics and this game tends to feel not as sharp at times... anyway, incorporating 480p support could have improved this.
The sound in the game is really great too. Music is very, very original and it really complements the unusual looks of the game. Voice acting is also really good, all of the characters sound convincing and original, and the sound effects are really good too. The only flaw is that the game doesn't support Dolby Pro Logic II and it would have been greatly benefited from this option (as RE4 was), but the real problem is that if you have DPL2 enabled, the game sounds odd and it sends erratic sounds to the speakers, so the rear speakers sound instead of the front ones. It really confuses you in the game, so I had to turn it off (unlike in other games without DPL2 support which just have a more dispersed sound).
This game is really a love-it-or-hate-it game. The game's mechanics are very simple but they do the job: you can only walk forward or turn around and go the other way around, it's like if you were walking over a rail; when you hear a Heaven Smile (again, I emphasise it would have been cool to have DPL2) you must change to a first-person view to find it and kill it. The game has a lot of puzzles (like in the good ol' RE days) and some of them are a little challenging. This game can get really repetitive, as you must shoot A LOT of enemies, but as soon as you find another cinematic with a ghoul talking gibberish (literally) saying something that you don't understand at all will make you get even more interested on the game. The game's story is really good and ideal for anime fans, but it's really hard to understand; I can't tell much without spoiling but it ends up with a big dispute that could have the US and Japan go to war, all while delving in the life and origins of Harman Smith and the Killer7.
Another thing I must say is that this game IS NOT FOR KIDS. It really deserves its M rating, as it has very strong scenes of violence, some sexual content and a lot of swearing, besides, its story is really hard to understand for kids and unappealing to them, and the pure gameplay won't keep 'em attached to the game. The story is really strong and it can get really scary and creepy, because it can get really sick at times.
As bonus features for finishing the game you have additional difficulties, which most likely you'll want to explore to try to figure out the story, as it's most likely that you won't have understood it on the first pass. Actually, this is its strongest replay value element, as the story is really intriguing. At first your only trouble while playing on the default difficulty level will be the puzzles and getting accustomed to the controls, but the other difficulty levels really test your skills, specially the Killer8 mode, which I found really hard.
Overall, this is really a great game that is quite innovative, but it's not for everyone. If you enjoy more non-stop non-repetitive action with very little-to-no thinking, then this isn't your game, but if you enjoy a lot of thinking and using your brain more than the trigger then this game is for you. Hope this review was useful, as this game is really hard to describe, you musn't play Killer7, you must experience Killer7.