If you call it a shallow after playing Shura and Shigurui, then how does any video game entertain one such as yourself?
First off, DO NOT PLAY MUSO (easy mode). Then you can mostly get away with button mashing and figuring out the trades of actual smart combat.
Visuals are stunning. You will stare at the background and forget you have to fight. Characters are magnificently styled and animated, the whole game is a giant feast for the eyes. Arguably the biggest artistic achievement in gaming since Okami.
Music is classic and usually catchy, spot-on with the Japanese mythology theme. A few missed songs here and there in my opinion, but overall a fantastic soundtrack. Voice acting is in Japanese, and is of course, great. Though rabid anime watchers may be confused by the ancient style of speaking, but it's good for them to get a dose of reality every now and then. The sound effects are adequate, I would not say they stick out especially compared to most games, but then again I can't think of a single game where sound effects are amazing off the top of my mind.
Combat is hardly boring. I played this game for 10 hours non-stop, when usually I have to stop after a max of 2-4 hours with most games due to lack of interest. If you think the combat is repetitive... umm, what? Have you played any other action games? Shooters? RPGs? MUCH more repetitive than this game, so I have no idea what you stuffed down your pipe. A lot of the key aspects of combat are decided by which crucial choices you make over having a vast array of choices, yes, but it is still a wonderful system. Try Shigurui Mode, where you may not get hit ONCE, and then you will quickly learn how astounding the combat system can really be. Even a small group of enemies can catch you off guard or surround you and that's the end of you. Bosses usually need analyzation of their intriguing attack pattens and are very very very fun to take on, makes me wish for a Boss Rush Mode. People complain of no death penalty, but really, on Shigurui Mode this is more of a godsend. I also never understood what was so great about having to take time to reload your game and redo everything you have already done. Where's the fun? I much prefer just loosing the 30 seconds (or in the case of bosses and challenges, sometimes multiple minutes) and allowing to retry at what I just lost. I will summarize that in combat, what you have to keep in mind is which attacks can break your guard, which attacks you can guard by attacking, when you have to actively guard, when you should evade and how (run/roll/zoom across the screen), when to use specials (and abuse their invincibility frames), and make sure your blades do not break! Three blades seems like a lot, but often all of them will be on the verge of breaking in the heat of battle and you will just have to run around madly until you can block again. There is more to it than this, but that's the basics. This is of course in Shigurui Mode, as in Shura you can of course use healing items to get your HP back. But honestly, I found Shigurui Mode to be the greatest way to play the game, despite rendering healing items obsolete for the most part.
You can play as Momohime and Kisuke, and depending on how much the game immerses you (and how many times the bosses kill you on Shigurui Mode - for me it usually took between 5-20 tries), each character's Story will take 5-10 hours to go through. I will say that time will most likely be around 8 hours per character. However, each character than has 2 more endings to unlock (accomplished by meeting in-game conditions before taking on the final boss), and there are still lots of the 100 total blades to forge (with many different specials), as well as large amount of challenges to take on, along with a few secret bosses. Some of those challenges will leave you shaking your first, as they take forever and are VERY hard, you may have to search out certain items just to beat a few of them. For a 2D sidescrolling fighter, it is QUITE lengthy, a wonderful surprise when I actually realized the playability of this game.
What are some bad aspects, as no game can really be perfect... well for one backtracking does sometimes feel a bit too over the top, even with the use of Bronze Mirrors. However, the world is gorgeous, just stunning, so I really did not care, but I can see how some may. But after you win you can warp to any shrine you want to and the problem is solved. A little more variety in the battle system would never hurt, it can't exactly be called very complex. But it is FAR from shallow. Can't help but mention that translation is sometimes cut a little short due to lack of space or mildly edited (calling a Nue a Chimera in a game about Japanese mythology was a big "...Why?" from me), but most of us will be oblivious and not notice these things. I mean if you ARE able to, why don't you just play the original Japanese version to complete the feel? One thing that would be fantastic for this game would be an art gallery and a music gallery (the wall scroll preorder bonus does sort of serve as an art gallery, but still, there were definitely much more sketches and concept art), but it's not worthy to cry over such a thing. And a Boss Rush Mode really would just be amazing beyond belief, but also nothing to cry over. But I really saw no major problems in my opinion.
To end it, I have to say, this game's addictive gameplay left me brooding about having to get back to life, and mixed with the wonderful music and mind-blowing art, Muramasa has officially become my favorite 2D Action sidescroller of all time.
Definitely a gem, 2D fans should not miss this one.