A legend is reborn.
There is no disputing Chrono Trigger's importance to the Japanese RPG genre. Combining talents from both Square and Enix, along with animator Akira Toriyama, the game is truly a "dream team" project. In some respects, its stature within the video game realm is parallel with such legendary collaborations as Kind of Blue and Raiders of the Lost Ark. And, like these pillars of music and film, Chrono Trigger is timeless. Its technology may be quaint by today's standards, but the game itself hasn't aged a day.
With the Nintendo DS version, Square Enix (now a single company) departs from its lavish remake style and instead presents Chrono Trigger almost exactly as it existed in 1995. The graphics and sound have been restored to some extent, and the translation has been appreciably revised while presenting no jolting differences with the original English text. Most fans of the game are unlikely to notice these slight differences, while newcomers will see a Super Nintendo game presented as such. A new DS presentation mode cleans up the display by moving status information and menus to the lower screen; this style of play is recommended even if you ignore the touch controls, which are inelegant and wholly unnecessary.
There are several gameplay additions, all optional and of varying quality. The first to become available is the Arena, which is accessed through a new portal at the End of Time. You receive a monster to train for special battles, but the training itself is automated, and the result is largely dependent upon which item you give to the monster. This feature is definitely the least interesting addition.
Upon obtaining the winged Epoch, you'll gain access to a new area, the Lost Sanctum, which exists in Prehistory and the Middle Ages. It's a secluded village of friendly Reptites, surrounded by some new battle areas that are based on familiar environments: forest, swamp, cave, and mountain. The Lost Sanctum is essentially a long chain of "fetch quests" that involve repeated transfers between the two time periods. Few of the tasks are memorable, and the rewards mostly consist of gold coins. Considering the hours required to complete this area, its blatant recycling of assets, and the nearly useless product of your labors, the Lost Sanctum is a shallow way to extend the game's length.
Dimensional Vortices are far more engaging bonus content, but they don't appear until the game has been completed once. You can either load your last save before fighting Lavos and warp out to seek the new areas, or you can play through a New Game + file until you have the ability to fly to the vortices. Either way, you'll find these new areas to be challenging. Each Dimensional Vortex begins with a series of rooms from earlier in the game, which you must traverse in exactly the same way as before. The next part consists of a new "dungeon", with fresh puzzles, epic treasures, and some new enemies, yet remixed from familiar areas like Death Peak and Geno Dome. The climax of each area is a boss battle against an evil doppelganger of Crono, Lucca, or Marle. These fights can be quite difficult and may require special preparation (such as equipping elemental armor), but if you emerge victorious, the corresponding character in your party will gain an extra status boost in Speed, Strength, Magic, etc. Even combined, the three Dimensional Vortices are quicker to complete than the Lost Sanctum, but they are far more interesting to play through, and the rewards are much more useful.
You'll need those stat boosts and superior weapons to tackle the final bit of bonus content: an ultimate boss battle that is far more difficult than any form of Lavos. Defeating this mysterious new enemy is probably going to require a few trips through New Game +, but that's perfect for devoted fans who are already eager to take multiple paths through the story. The new boss also provides a nice link between Chrono Trigger and its quasi-sequels, Radical Dreamers and Chrono Cross.
Overall, the extra features do little to justify the infamous "Square Tax" that makes Chrono Trigger and other Square Enix RPGs among the most expensive DS titles. This is essentially a Super Nintendo game being repackaged and sold to you for more than full price; however, the value proposition may be easier to accept in light of secondary market prices for the original cartridges. Regardless of price or underwhelming extra features, this is an excellent and authentic port of my personal favorite game of all time, and one I would recommend to virtually anyone. If you can read, you should play Chrono Trigger, and the new DS version is an accessible way to do that.