Ultimate might be putting it a bit too strong.
The DS has succeeded as a platform largely because it attracts software that works well on the go. Games such as Brain Age and Tetris DS are great pick-up-and-play titles, and are two of the system's most notable success stories. Games that try to recreate the console experience on the handheld have been somewhat less successful, and Marvel Ultimate Alliance 2 for the DS suffers from trying to do too much on a system meant to do the small things well.
The game's primary problem lies in the lack of easily attainable multiplayer. The game is clearly designed with multiplayer in mind, but it requires each player to obtain their own copy of the game. While it is understandable that the entire campaign mode could not easily be handled on two or more systems via single-card multiplayer, it would have been nice for some sort of compromise, as it is very unlikely that most owners of this game will ever experience it in way that the developers intended. The game has you staring at four characters for the entire duration of the campaign, allowing the player to swap between any of them; it's almost as if you are being constantly taunted about your inability to play the game in multiplayer mode.
The game, the first in the series on the DS, tells the story of the Marvel Civil War. It's a recent well-loved story in the comics that tells of a rift between superheroes when a law is passed that requires all superheroes to register with the government. The game forces you to choose a side, meaning that depending on which side you pick, you get a different perspective on the second act of the game, with slightly different objectives over the same levels. The choice will cost you the chance to play as certain characters, as some, such as Iron Man, Venom, and Captain America, are exclusive to one side or the other. Others, such as Spider-Man and Wolverine are universal and will follow you to whichever side you choose.
Another consequence of choosing not to compromise on the game's premise when putting it onto the DS is the controls. The game plays with the standard D-Pad and face buttons, using the touch screen only in a few mini-games during boss fights and for each character's special attacks.
The drawback to having the special attacks on the touch screen is that you have to take your hands off of the regular controls to use the stylus to perform them. You can also use your fingernail, which is a little more convenient, but lacks precision. It wasn't until the middle of the game when I realized that I could also hold down the right shoulder button and use it in combination with the face buttons to achieve the same results. Until I discovered this, the special attacks were sorely underused. You have less freedom with the fusion attacks, which allow you to combine powers between two heroes. These attacks require you to drag the stylus from the center of the touch screen to one of four icons. While powerful, I found the attacks to be so inconvenient that I rarely used them.
The game also tries not to compromise on the visuals, putting a rich 3D environment on the DS, and in this decision, they succeed more than they fail. There are some frame rate problems at points in the game, but for the most part the 3D engine functions well. All of the characters are fully recognizable and imagined in 3D models. Unfortunately the animations aren't handled quite as well, and most of the time it looks like your favorite Marvel character is just flailing around in front of an enemy until the enemy falls over. Most of the environments aren't anything spectacular, but there are some exceptions. There is a scene where you can see two giant superheroes in the background fighting while you cross a bridge in the foreground, and this scene does much to give the game a sense of scale. Better yet, you end up fighting one of those two giant heroes later in that level as a boss.
Much of the time your fellow Super Heroes tend to just follow you around and attack any nearby baddies. Sometimes, however, they stand there as you march forward through the level, leaving any enemies encountered to be dealt with by you one-on-one. You can bring them forward to your position by swapping to them quickly and then swapping back to your preferred character, prompting them to warp instantaneously to your position.
Because you'll be fighting these enemies largely on your own, with only occasional help from your brain-dead compadres, the game's difficulty has been noticeably reduced. Although the game gives you nine different attacks by default, the game is easily finished by using only the normal attack button. Enemy AI is reduced to "approach, melee" or "approach, shoot" and most of the time you can easily succeed by taking the same approach. Even if your character dies, you can easily switch to one of the other characters in your group and spend some earned XP to revive the fallen hero. Having all of the characters in your party dead at the same time is so uncommon that it only happened to me once in the game, and that was when I was learning how to fight the boss of the first stage.
The game does have some light RPG elements, such as leveling up your character and spending coins on upgraded abilities, but if you choose to ignore this aspect of the game then your characters will be upgraded automatically. As a result, the RPG aspect of the game is entirely optional. If you choose to upgrade your characters, then you will have some control over how the characters evolve. Each of the Super Power attacks can be upgraded separately, as can your passive abilities such as melee strength and defensive prowess.
Marvel Ultimate Alliance 2 is a good first step for a complex 3D brawlers on the DS, but as the game is tailored to none of the strengths of the platform, many problems exist. If you have a friend who's willing to pick the game up and join you for the playthrough, then a great time could be had. Most players, however, will play through the game solo and be bored with it before the conclusion.