Difficult? Perhaps. Waste of money? I don't think so.
Graphics 8,5/10: A nice conversion from the Arcade/Saturn port on the DS, the frame rate is very smoothy and also pack well with game game speed. Nothing much incredible to be analysed tought, the only "flaw" is the screensize, but that's an Hardware "problem" and not the game itself(Sorry Nintendo Fanboys, I love my DS so please don't take this personally). Puzzle Kombat, despite being a very....peculiar game, have a nice and humorous graphics with overheaded 3D character models based on the late years of the franchise, with interesting background graphics, but that's all about it.
Sound 7,0/10: There's a perfect translation to the DS, you can hear all characters sound and scenario music exactly as it were on the arcades, but being honest, the translation was perhaps, much loyal to it's origins. The only difference between the character's voices is the genre of the kombatant, women sounds equal as other women, as the guys sounds alike the other giving no space to upgrade. Can't complain about the musics since it's classics on the mix, no trouble at all.
Gameplay 6,0/10: Oks, the main flaws as you might expect came from here, but it isn't so bad as you can imagine. The biggest complain is about the gameplay difficult, since it's really, and I mean REALLY difficult to beat the upper level opponents in the game. I hate to say this, but passing throught endurance is really an ordeal for a MK player, since AI foresee your attacks and truly counter according not big trouble if your consider the game's proposal, but sometimes it's seems so much cheap the way it is, and maybe some pro-players might think this is a noob (no, not the saibot) complain, but it's obvious that the lack of an option regarding difficult is a truly problem and makes the game less attractive to newcomers. Puzzle Kombat, despite the funny design, is an obvious copy of Puzzle Fighter with little fun to offer since the gameplay is very straight and somehow easily boring. Multiplayer is fine, if you got some skills on the game, since many who join the online rumble simple is the most slaughter machine or just a coward who can't take the beat and concede before the match is over.
Replay 6,5/10: Despite the flaws mentioned UMK3 can be a nice and cool quick game experience if you are looking more a reflex than a brainbashing game, there's 3 characters to unlock(via in game code) and a nice rooster to keep you entertained for sometime if you are willing to give a chance. Puzzle fighter is too weak in my opinion to make the game, but since is a in-product spinoff can break the boredom for a few moments.
Overall 7,5/10: UMK3 for DS is a Good port and a Game especially if you need some gore on your portable. Despite some gameplay nuisances it stills kicks some nice action on the screen, but you need to really try it is you intend to see what the game can offer for real, since it have a nice rooster and the good and classic feeling of 2D brawl.
Ps: There's also a Secret Character that can be unlocked during the matches by pressing and holding an sequence of buttons before the match start with an unique character. Try you look.(or rather, just Google it)