The locations and level design are varied enough in Legend that the game stays from being repetetive or boring. There are a few vehicle levels scattered throughout including a couple of motorcycle levels that are successful in varying the gameplay a bit, although the graphic quality and control does drop slightly. The touchscreen is used in several ways that help to make the DS version unique, and are also fun additions in their own way. For starters during
basic gameplay the touch screen acts as a weapon and item select, which works well enough, and design of this screen varies slightly for each level keeping it from being dull.
When you approach an enemy in the game an 'A' bubble will let you know you can hit that button to change the touchscreen into a front on view of the enemies in your immediate area. You can then tap on them with the stylus to fire your selected weapon. This is a bit clumsy, and enemy AI never ramps up to the level it should to make this challenging, but again is successful enough in providing a different gameplay experience, and is better than simply pressing a button. Also, at certain swimming spots the touchscreen will transform into an extension of the top screen, making it possible for Lara to dive down into the depths below and swim around. 
This is a really cool effect that I wish had been used a little more, and possibly in other ways such as dropping down into tombs or the like. Finally, there are medallions littered throughout all of the levels which can be collected to unlock extras outside of the main game. Often you will just press Y by the medallion to collect it, but at times you will be asked to dust the dirt off it with your stylus, or blow the sand off by blowing into the mic, which is reflected in a graphic that will pop up on the bottom screen.
The graphics in Tomb Raider Legend on DS are kind of a mixed bag. In some places the hardware is pushed quite extensively to give some well textured 3-D environments, while in others textures are blurry and unimpressive. Lara animates fairly well as she acrobatically navigates the varied terrain, but obviously is hardly going to get anybody drooling over her on the Ds. The menus and overall presentation of the game are above par for a third party offering, but the game is not without its frayed edges.
You will find numerous graphical glitches throughout; everything from poor collision detection to flickering sprites, as well as a fairly limited draw distance. It's nothing that's going to interrupt your progress in the game but it is also hard to ignore. On the sound design front you will find moody choral arrangements and other atmospheric tunes, but average effects in terms of sound effects. The loops on the music are a bit short, and also the compression is noticeable, but they reflect and support the atmosphere of the levels well enough that this can be forgiven.
Legend turns out to be quite a meaty adventure on the DS. The single player still may be over a little quickly for some, but there are plenty of unlockables to keep players coming back, including a cheat system and concept art. There are also a few simple minigames utilizing the touchscreen that can be unlocked, but nothing that is going to knock your socks off. It is worth mentioning the title does have a multicard multiplayer option for two players, yet we were unable to trial this for you as Eidos only sent us one copy of the game.