Admittedly, when I first read through it, I thought the manga was a poor adaptation. However, taking the merits of the original game and the length of manga into consideration, I can say that the author did fairly well.
Storyline is entirely hit or miss depending on whether the reader has played Clannad and Tomoyo After. The story moves way too fast with not enough transitions for a reader new to the series to fully grasp the situation. Having watched/played Clannad isn't a necessity, but it does help flesh out the story background.
If you've played Tomoyo After, though, that's another story. Taken on its own, before or after Clannad, the story is anything from good to great. However, if, like me, you have already played the game you'll be glad that it's only 4 chapters and didn't waste more than 30 minutes of your life. Some events are added in manga that doesn't really add anything to the storyline. Not only that, due to the extremely short length of the manga, many events and even characters are outright missing.
Speaking of characters, this is probably the strong point of the manga adaptation. Even though a main character from the game is missing, the rest of the characters do have some depth despite the length deficit. Both Tomoyo and Tomoya will grow on you, each with their own distinct personality, problems, and viewpoints.
Stylistically the manga stayed pretty close to the game, which isn't a bad thing at all. Especially, the manga does a great job portraying fear and insecurity each person felt at different points of time, which really helps convey some of these experiences and emotions and make readers feel for these characters.
Did I enjoy the manga? Definitely not when I first finished it. However, this is not the fault of the manga alone. Annoyances like missing characters aside, I never liked the ending in the original game either. However, it is a very moving tale, and all in all I enjoyed the story's progression towards the disappointing ending.
As you can see from the overall score, even though I pointed out a lot of the negatives, my lasting impression is still a very positive one. There are far more people who hasn't played Tomoyo After than those who has. Taken on its own, the manga is still a great story with memorable characters, and as such I recommend to the majority of people who read manga. The only gripe I can see is the brevity. Four chapters is definitely not enough to develop these characters, and the events seem rushed. That, and don't play the game before you read the manga.
