While it does maintain some good qualities, Dawn of the New World is the most disappointing Tales game to date.
Let's start with the story, which takes place in the same universe as the first Tales of Symphonia. After the two worlds (Sylvarant and Te'thealla) are reunited, tensions between the worlds grow, and the weather around the world has become chaotic. You play as Emil (we'll get to him later), who early on takes on the task of protecting Marta (her too), who is trying to awaken Ratatosk, the summon spirit of the Giant-Kharlan tree that was destroyed in the first game. The plot complicated, needless to say, and at first the story doesn't do anything too atrocious (aside from the absurd amount of unskippable cutscenes). However, as the game progresses, the story just becomes more and more convoluted, and it feels like characters in the game are pulling solutions to there problems out of nowhere, especially towards the end.
As for the character design, it is mostly solid. All of the playable characters from the previous game are included and are playable (sort of), most of the villains are well designed, and Tenebrae, a Centurion that accompanies you (imagine a demon panther), is probably the best part of the game. However, some character design choices fall flat on their face. While Emil and Marta become tolerable later in the game, they are unbearable through the first half or so. When one of the plotlines is finding the courage to tell someone "Thank you," there's a major problem. Not to mention a couple of the villains (a sadist and a man obsessed with her) and just terribly designed. Again, the characters aren't too bad, but there have just been other games in the series where the design was so much better.
The battle system is the same battle system all Tales fans know and love. Do combos, use artes, kill enemies, feel like a bad ass, and for all of the things that were tampered with in this game, this is the one thing (thankfully) that was mostly left alone. In fact, one of the few good things about Emil is his move set. However, while it doesn't tie directly to the battle system, there is one problem the game has that is related to it - monster collecting. Sometimes at the end of a battle, you can make a pact with a monster and have it fight for you. The problem with this is is that monsters are always weaker than humans, and often they will only give you two or three characters to fight in your party,, forcing you to fight with a weaker ally.
And there are so many little things the game does wrong to. The absence of a field map to fight monsters, the fact that none of the original voice actors returned, some poor menu design choices, the overhaul of the cooking system, and so on. All in all, this game is at best barely playable, and there are much more superior games in the series than this one.