-At the beginning, you can select two different scenarios, each devoted to one of the two main characters; apparently, they only change some sets of events rather than the whole plot, and you can enjoy the game even playing only one of them, even if some people advise to play both in the Jude-Millia order. Useless to say, this does provide a nice boost to replayability, which is good considering the main quest itself is apparently in the 30 hours range.
-102 sidequests are available during the game.
-Bigger maps, sometimes with multiple levels; you can jump and climb at set points to reach new areas. The maps themselves are organized in the same way as Tales of Graces f to provide an interconnected set of areas; so, while there are indeed linear areas (just as in Vesperia and Graces), you won't find a FFXIII-like corridor from the prologue to the final boss, thankfully.
-60 of Aifread's Treasures (Aifread being Tales of's legendary pirate, for the ignorant landlubbers) are scattered across fields and dungeons.
-A customization system centered on a spiderweb-like scheme that works in a similar way to FFX's Sphere Grid.
-A generally sleeker presentation (even aside from menus and events, having Ufotable instead of IG really helped imo, and apparently Sakuraba did a nice job with Xillia's sountrack).
-Rotable camera, third person view instead of the fixed camera employed in all previous 3d Tales of games.
-Xillia's shops level up during the game, either by buying items or by improving them using materials found in the fields. Those improvements carry over to each new shop of the same category.
-You can swap your party members during battles (I don't mean your controlled character - you can bring people in and out of battle like in FFX or Mana Khemia as soon as you have more than four characters).
- New Link Artes that let you coordinate two characters in order to make unique moves (not all characters have them, and they can have some issues when at least 3 gamers are playing together).
-Each characters has unique skills you can trigger during combat to make their play style more unique. Please see this post:
http://www.neogaf.com/forum/showpost...&postcount=799
-A fusion of CC and TP, with the CC-like AC points being used for normal attacks and TP being employed for traditional Artes (it's somewhat a Graces\Vesperia combo, if you will), providing longer normal attack chains and more combo opportunities.
-Aerial combos are back, if you missed them in Graces.
-One Mystic Arte per character, with a Jude+Milla Dual Mystic Arte
-Three types of skits: long (traditional) skits, short skits (think the Dragon Age banters while you explore areas) and battle skits. The game has some 241 long skits.
-An Ex Dungeon.
-An Arena (no cameo battles, be warned).
-The Fell Arms.
-Four costumes (2 for Milla, 1 for Jude, 1 for Alvin) are in the game, the others are sadly available as DLCs.
-Optional bosses.
-Joke weapons (rewards in the Arena)
-Grade shop (grades are organized differently than Graces f, though)
-Five difficulty modes (Easy, Normal, Second (Moderate), Hard, and Unknown)