Yakuman DS (and the Wi-Fi enabled re-release) are part of a long-running series of Japanese style Mahjong games published in Japan by Nintendo. Due to the relatively limited interest outside Japan in Japanese style Mahjong, often called "Riichi" or "Reach" Mahjong, these games were never released outside Japan.
So what is Mahjong? The real game of Mahjong has nothing to do with setting up an intricate board of tiles, and then matching them two at a time to remove them. Unfortunately, since that game uses Mahjong tiles, and it's far easier to program than a true Mahjong game, that is the majority of what you will find if you search for Mahjong games released outside Asia. The real game of Mahjong is originally a Chinese game, estimated to have been created around 1850.
Here is a very basic explanation of how to play the game: Your goal is to build a collection of 14 tiles consisting of 4 melds and a pair. A meld is defined as either a set of three identical tiles, or a run of three sequential tiles of the same suit. A pair is two identical tiles. Each player is dealt a starting hand of 13 tiles. On your turn, you take a tile from the wall (the stack of available tiles), and if you don't have a valid hand (or if you want to hold out for a better hand), you discard a tile. It may be the same tile you just drew, or another tile in your hand. So as you play, your hand should begin to take shape. If this were all there was to it, Mahjong would make for a pretty simple game, and probably not that interesting.
However, there's a twist - if an opponent discards a tile that you can use to complete a meld, you may be able to immediately steal it! You can always steal it for the win, or to give you a set of three identical tiles. To steal it for a run of three sequential tiles, it needs to be discarded by the player immediately before your turn (since runs are generally easier to get). So now, you are not only playing on your turn, but you need to be vigilant in watching what the opponents play so you can try to deduce what kind of hand they may be building, and also to steal a tile if the opportunity arises. The upside to stealing a tile is that it can help you complete your winning hand faster. The downsides are that those tiles are now locked in that meld and cannot be changed for the remainder of the round, and you are telegraphing to your opponents what kind of hand you are working on. Also, an open hand is often worth fewer points than a concealed hand. When you claim a tile to complete a meld, you will then be the active player, and the stolen tile counts as drawing a 14th tile, so if you don't have a winning hand, you'll have to discard a tile afterwards.
Note that 4 of a kind is also a valid meld, and if you claim this meld, you will draw a new tile before discarding. A 4 of a kind is considered to be 3 tiles for the purposes of creating a 14 tile hand. (So if you have a 4 of a kind, your winning hand will technically have 15 tiles, but it still counts as 14).
The first player to complete their hand wins the round, and scores based on the composition of their hand. The more difficult the hand is to create, the better the score will be.
So how does Riichi Mahjong differ from traditional Chinese Mahjong? Firstly, there are a different number of tiles used - 136 in Riichi vs. 144 in traditional Chinese Mahjong. The 136 tiles consist of 4 identical each of the following suits: 1-9 Souzu (Bamboo); 1-9 Pinzu (Circles); 1-9 Manzu (Characters), East, South, West, and the North Winds; and Red, White, and Green Dragons. The flower and season tiles from a Chinese Mahjong set are not used in Riichi Mahjong.
Secondly, Riichi Mahjong has the concept of Yaku, which means that your hand has to contain at last 1 scoring element, or Yaku, in addition to meeting the four melds and a pair requirement, in order to be able to win. It may help to think of yaku as being similar to a poker hand. A Full House in poker consists of a pair of one number, and three of a kind of another. Similarly, a Yaku in Riichi Mahjong requires specific scoring elements to win.
One other thing that Riichi Mahjong does is the "Riichi" mechanism. If you are one tile away from winning, and you have not taken any discarded tiles, you may declare Riichi, which lets the rest of the table know you're one away from the win. You're no longer allowed to change the makeup of your hand after that - when you draw a tile, you must either call a win or discard it. You can also win off an opponent's discard. Declaring Riichi also counts as a Yaku, so even if your hand didn't have any before, you can now win the round since declaring Riichi brings you to the 1 yaku minimum.
Speaking of discards, that's another strength of Riichi Mahjong. In traditional Mahjong, everybody discards into the same pile. In Riichi Mahjong, you have your own personal discard pile where you set your tiles. This serves two purposes. When you win a hand, if you drew the tile yourself, all the opponents share the payment to you. If you win from a discard, the opponent who discarded the winning must pay you the full amount. This means that your play strategy early in a hand may be aggressive, but then when someone declares Riichi, you may switch to discarding safer tiles to avoid discarding the tile that will win them the round.
How do you know what tile is a safer tile? That's where the Furiten rule of Riichi Mahjong comes into play. Furiten is sometimes translated into English as "Sacred Discard." What it means for the player is once you have discarded a tile, you cannot claim an identical tile from a discard to win the hand. There are some additional restrictions as well that can come into play, but that's the basic rule. So as the round nears the end, if you see an opponent has already discarded a tile that you have another copy of in your hand, you can discard that tile without fear of that opponent claiming it (and consequently, you being responsible for the full payout).
The last major difference in gameplay between Riichi Mahjong and Chinese Mahjong is the Dora, or bonus tile. At the beginning of each round, one tile will be flipped over for all to see. This tile is the Dora indicator. The next tile in sequence will be the Dora tile, which adds additional points to your score if you have one or more in your hand when win the round. So if the 2 Souzu (Bamboo) tile is flipped, then the 3 Souzu would be the bonus tile. The Winds go in order from East, South, West, North, and the Dragons are ordered Red, White, Green. The Dora will also wrap around, so the 9 Souzu would indicate the 1 Souzu as the Dora tile. Any time a player claims a 4 of a kind meld, an additional Dora indicator is flipped, up to a maximum of 5 Dora indicators. They also stack, so if you have two or three of the same Dora indicator flipped, the respective Dora tile would be worth 2 or 3 times the value. The Riichi mechanism is integrated into the Dora indicators as well. If you win the hand after declaring Riichi, you'll not only get the bonuses from the dora tiles indicated, but you'll also get to flip over the tiles beneath the exposed Dora indicators, to discover up to 5 additional Dora tiles!
There is also a large difference in how you score in Riichi vs traditional Mahjong. However, scoring is a bit more complex than I want to try and explain fully in a review. The short version is that you score two different kinds of points, fu and han. Fu are calculated based on the kinds of melds in your hand - 3 of a kinds, and runs that start or end with a 1 or 9 are worth fu, which will raise your score, but not by much. The big scoring comes from the han points. Yaku convert directly into han, so if you have multiple yaku in your hand, they start to add up quickly. Additionally, Dora tiles are also worth 1 han each. Once you hit 5 han, the fu points don't even matter anymore, and your score begins to really increase dramatically. A han value of 13 or more gives you a Yakuman score, which is worth 32,000 points (or 48,000 points if your seat wind is East). There are also specific hands that are so difficult to get they automatically score a Yakuman.
There are a plethora of other rules and variants in Riichi Mahjong, and some exceptions to the rules ones mentioned above. If you're deeply interested in learning Riichi Mahjong, there are plenty of sites out there that can provide you with the more in-depth information that doesn't really belong in a review.
OK, enough about Mahjong in general, what about Yakuman DS? In terms of game flow, Yakuman DS delivers a pleasant Mahjong experience. The second screen is nice to have a place where the opponents' discarded tiles are shown. Playing against Mario characters is a lot of fun, and the game has quite a few voice clips, although I believe the majority of them are borrowed from Mario Kart: Double Dash. If you're in the mood for a more serious game, you can turn off the Mario faces and voices.
If you're still learning the game of Mahjong, try playing with the support function on. Lakitu will suggest the discards for you to make, and you can check with him on what hand he thinks you should build towards, and see how much risk there is to discard a tile for the other players to claim. If you're a super beginner, you can also play with your opponents' hands exposed, so hopefully you would never discard into a win for one of them.
I mentioned other rules and variants, and while some Mahjong games allow you to tweak the settings, I think Yakuman DS has quite a comprehensive menu of rules you can allow or disallow, to make the game more familiar, more exciting, or just to try something new. These range from things like including or excluding the red 5 tiles (which replace some of the standard 5 tiles, and can double your score), allowing or disallowing multiple winners from the same discard tile if it would complete more than one player's hand, whether a player can go into negative points, or if the game ends when a player is bankrupted, etc. Another rule that you almost never see in Mahjong games is that you can allow players to make mistakes and incur a penalty. For example, calling a discarded tile for a win when you are in a Furiten state would earn you a stiff penalty. Most Mahjong games don't let you make bad calls, and by default Yakuman doesn't either, but it's nice to see the game contains an option to allow it.
All these rules and variants are available in the Free mode, which is the default mode of play. There's also a Ranking mode, where you choose opponents and play them for points to go up or down a ranking scale to try and get to number one. The higher ranked opponents are markedly more difficult than the lower ranks, so there's a good balance of difficulty levels in the game to keep it interesting as you get better. The final single player mode is Challenge mode, which has you completing specific tasks against specific opponents with specific rules and conditions. For example, the first beginner challenge has you play with the victory condition being that you don't end up in last place. Later challenges may have you get a specific score, or beat a specific opponent, etc.
The game also supports Download and Play, so up to 4 players can play with a single cartridge. It's not a long download either. I tested it out and it took roughly a minute for the second system to download the client to play.
There's also a pretty big Mahjong glossary, although it is entirely in Japanese, so it won't help you unless you know the language.
I think if there's a general downside, it's the screen resolution of the DS. The discarded tiles are pretty small on the screen. This is out of necessity - people are often going to be discarding 15+ tiles each in a single round, and you need to be able to see all of them to play properly. However, some of the tiles are difficult to discern on the discards, although with a few plays you an get used to it and recognize them. The original release of this game was in 2005, so it's a fairly early DS game, and it certainly looks it. The graphics and animation of the characters are pretty simple as well.
As another downside specifically for non-Japanese speakers, Yakuman DS (like many import games) is in Japanese. Even if you have a basic knowledge of Katakana, some of the tiles have Kanji on them, which means you'll be a much better player if you can recognize a few characters. Most notably, the Manzu (characters) suit has Kanji on them from 1 to 9, and the Wind tiles are in Kanji. Thankfully, the game auto-sorts your hand (you can choose several different sorting methods as well), so the Manzu tiles you have will at least be in order. With the Wind tiles, since you can only match them as 3 or 4 of a kind, knowing which is which is slightly less important (although still relevant, since you need to know what your current seat wind and the round wind are, since 3 of a kind of either those will get you a yaku). The red and green Dragon tiles also have Kanji, but since they are distinguishable by color, that's not such an issue. You'll also need to either read or memorize the katakana for Chii (stealing a tile to complete a run), Pon (stealing a tile for a 3 of a kind), Kan (calling for a 4 of a kind, either stealing or self-drawn), Ron (winning off a discard) and Tsumo (winning by self-draw). They're kind of context sensitive, and will only pop up when you can do them, but sometimes two or more of them will appear if they would satisfy two conditions, so you'll want to choose the right one.
In Conclusion Overall, this is a really comprehensive package for anyone who has learned the rules of Riichi Mahjong and wants something they can play on the go, and customize to their liking. If you don't know how to play, you'll need to become familiar with the rules prior to playing. However, once you learn how to play, you'll find a remarkably deep, satisfying, and thoughtful game that can be as relaxing or as intense as you want it to be. Mahjong has often been called the game of a hundred (or a thousand) intelligences, and although I don't know if that's necessarily true, there is a lot to keep track of in the game, and a very high skill ceiling.
Beginners should start by focusing on creating valid hands. Once you do that reasonably well, you can start trying to create more complex hands, or hands that could be completed by multiple tiles. Once you have that skill, you can focus on reading your opponents discards to try and determine what kind of hand they are building, so you an avoid discarding a tile they will claim for the win. There's room for aggressive and defensive play, lots of skill involved in reading opponents, and sometimes a little luck in getting a good set of starting tiles to create that winning hand quickly. And it's kind of exhilarating to get a high scoring hand, especially against one of the tougher opponents. The rush of being one tile away from scoring a Yakuman is intense.
If you want to learn how to play Riichi Mahjong, check out the links I've posted to this review, or send me a message and I'll be happy to talk about it in more detail.
Note that there is a Wi-Fi version and a regular version of the game - as far as I know, they are identical other than one supporting the Nintendo Wi-Fi connection. Since Nintendo WFC is no longer in service, either game should provide you with the same experience, so if you're going to buy, just pick whichever one is cheaper.