Being an adaptation of a video game, ToA has to balance between two things:
1: It has to remain true and accurate to the source material for the diehard fans who are watching it for the label, while also
2: Keeping the storytelling format interesting to the viewers who've never played the game.
And I feel this anime has managed a balance between the two that you rarely see in any kind of adaptation. I give my feedback on the two points separately below, in order.
If you want to know how well it adapts the story:
Tales of the Abyss runs a story very much similar to what the game-players will remember while leaving out only the most minor of details, things that in hindsight even a die-hard fan would admit the story could do without.
For example, instead of using the scene where Engeve's villagers discuss the food thieves, the anime moves right from when Luke takes the apple without paying to being brought to the village chief, a smooth and clean transition that cuts out runtime it didn't really need. This even at times adds some realism; no slowly-sinking town so you can leave for three days to get the Albiore, it's sinking NOW and the Albiore just swooped in to save the day.
Best of all, while it cuts out the unnecessary portions, it adds some scenes the game could have benefited from: backstories that were originally only dialogue get actual flashbacks depicted.
If you want to know about the story itself:
The story centers around Luke fon Fabre, the spoiled, sheltered son of a noble who knows nothing of life outside the villa and is basically designed so that you'll hate him out of the gate. He's soon taken far away from his known universe into the outside world when Mystearica Grants (usually just called Tear) breaks into the manor to kill Van, Luke's swordfighting instructor. Feeling responsible for them being teleported away, she vows to get him home. This is where Luke's long journey of character development begins, as he has to learn of even the most basic of real-world concepts, initially not even understanding the concept of money.
As much as Luke develops, the story still manages to give plenty of screen time to the other five playable characters of the game, and let them develop sufficiently as well. Nothing is iced over, even traits that are initially portrayed as comical are of large importance to their characters. Guy's afraid of women? That stems from a deep trauma we later learn about. Anise is obsessed with money? She's got people around her who always need it. Their pasts and their connections to the villains are well fleshed-out. Only one villain out of many is your generic, power-hungry fool, and he was ultimately a pawn. The rest all have deeper motives for doing what they do, and you may even mourn the deaths of some of them.
This tale is centered around several varied but important themes such as being outside of the world you've known, defiance of what's claimed to be inevitable, prejudice based on the uncontrollable being unjustified, living with a sin that can never be forgiven, finding a reason for life, and why everyone deserves to live. If someone has lost their way to despair, they would likely feel a kindred spirit in Luke and find an answer through this powerful Tale.
