This game has everything I like in a game; interesting character design, quality voicework, a fair amount of customization, collectables, witty writing, excellent gameplay, awesome BGM, all wrapped in a package practically oozing with style. It's basically a "fun" videogame, which I find hard to come by nowadays. It's not often I'll try a game made recently and find myself losing track of time while playing, not wanting to let the controller(s) go. Even though the game is just a hack n' slash (a.k.a. beat' em up with weaponry)-style game, there is a LOT of things that went into the game.
Probably the most obvious quirk of the game I like, is how the speaker of the Wii-mote is utilized. I was astounded to see that I had a call in-game, and had to use the Wii-mote as a cellphone. But some of the smaller things, such as the variations in your combat style when using different beam katanas, or the many variations to the main theme that play throughout the various main story missions, or the way Travis' room becomes more and more decked out as you collect trading cards, and even the references to japanese otaku culture amaze me even more. There are literally thousands of things that make this game amazing, and I could make a pretty long list detailing why I like this game so much.
What makes the game even better, is that part of the game mechanics remind me a lot of Samurai Champloo: Sidetracked, which was an offbeat hack n' slash game for the PS2 that I enjoyed. It almost feels as if SC: Sidetracked was merely a stepping stone in the process of making this fantastic game. There are a lot of similarities between the two game mechanics wise, with NMH being a much, much, higher quality version of SC: Sidetracked. NMH takes everything that made SC: Sidetracked fun, and improves it 10x fold, while fixing everything else that made the game frustrating (like the level design).
The downside to NMH however, is the rather vulgar language and the excessive gore may turn some people off. Honestly, the gore doesn't phase me as much since the level is rather tasteful, and the majority of old school videogames involved violent actions no matter how cute the game may seem. (Super Mario, MegaMan, and Mega Twins, anyone?) Vulgarities I don't mind either, though that's just me.
Another thing that I can see turning people off, would be the combat system, and the huge spike in difficulty when it comes to facing off against bosses. NMH's combat system is very unique, and very fun once you get the hang of it. Thankfully, the learning curve for the basics is not steep at all, and those are all it takes to take down most of the generic enemies. However, players will find that they'll need to learn the more advanced side of the combat system if they want to effectively take on the bosses; the earlier, the better. However, learning how to fight effectively in NMH is rewarded beyond just making the game simpler. There are challanges which grant you money based on your skills with the combat system, the majority of which include battling without taking a hit, or dispatching enemies quickly and effectively.
In short, NMH is a game that practically gushes creativity, style, and uniqueness. The only downside to the game, is that it is not suitable for all audiences, and that the gameplay may be a little too unique for some. But otherwise, it's the most fun I've had with a game for a while. I HIGHLY reccomend this title, to anyone mature enough to handle blood, guts, and cussing.