Angel Heart starts by following professional assassin (trained from a child), Glass Heart, as she attempts to escape from her life of killing, by ending her own. But after a heart transplant, and a couple of years sleep, she's good as new. The new heart brings it's owner's spirit with it, and refuses to let Glass Heart die, and so, Glass Heart escapes, to try and find out about the person the heart belonged to.
The series is made up mostly of seperate story arcs, the first following Glass Heart's escape, the rest following her new life as she starts accepting missions to help people in dire situations, and in doing so, learning about life.
The first arc is generally more plot-driven and a lot more fast-paced. After the first arc, things start to meander into character development, with far less in the way of action. If you have a short attention-span, you should be able to watch the first arc alone without worries, as it's a self-contained story.
Since the series mainly follows character-development, the characters are important, and in my opinion, they've done well. The regulars are a variety of interesting characters that you should have no trouble watching for the length of the series. The characters that need help are also well made, with realistic reasons for needing help. Honestly, some of the coincidences in the series are a bit of a stretch, but still, they're well used.
I'll also note that there are a fair few flashbacks about how Ryo became the City Hunter, and his relationship with Kaori. These may have been covered in the original series, but if you haven't seen it, then these will fill in a few gaps.
This is a 50 episode series, but there's no real 'ending', things simply keep going without any further resolution beyond that of the first arc. And it is kind of disappointing. Also, with so many episodes, despite the series being good, it does start to drag towards the end.
The art goes for a more realistic style than usual, (most notably, the eyes are smaller) and it's well done.
One thing I wasn't expecting from this series was that it contains a fair chunk of humour. The humour is mostly character-based. For example, Seaba Ryo, the City Hunter, is a bit of a clown, and lot of a woman-chaser.
The realistic art-style makes seeing the silliness of some situations that much stranger, and in my opinion, that much stronger. For instance, the gigantic wooden hammer (that makes only a couple of appearances) is obviously ridiculous, but it does actually look like a real object.
To summarise, this is a good, mostly serious, character-driven series, that involves combat specialists helping people out of dangerous situations, though there's not that much action after the first story. There's also regular silliness to mix things up.
And people with short attention-spans may only want to watch the first few episodes.
You'll just have to decide whether to watch City Hunter first. If you haven't already.
