Well for starters you look at the studio producing it and you see Studio DEEN,which in all fairness has produced some great series (such as Rurouni Kenshin,Higurashi ) but overall they usually lack the talent,resources and production values that other companies have and released a lot of mediocre/bad series.
Fortunately their work on Giant Killing is on the good side of the "balance spectrum".
The story revolves around a initially weak team by the name of East Tokyo United ,playing in Japans first football league with very little success.Everything changes however when one of their former star players,now a coach ,returns from England to take control of things and manage the team trough their efforts in facing tougher teams.
So yeah basically its a "from zero to hero" type of story,fairly straight forward and quite well done for the most part.
Starting off with Tatsumi Takeshi the manager of the team and main character of the series,its quite obvious that the author wanted to make a character based on real life manager José Mourinho and for the most part it succeeds in doing so :arrogant ,all-knowing ,while being self aware of all these traits.But still being a excellent manager who has a keen eye for the players under his command and knowing to use their full strength.
However often times in the series he takes a very laid back attitude towards training and preparing the players for their next match,even as far as going for a childish "the one who has the most fun will win..." or "let the players decide on their own" which can be very debatable all things considered.
Also in the anime we don't get to see his back-story properly as to why exactly he left the ETU team,his play style, why he retired rather early.... This most likely is covered in the manga,but the anime does not mention these things they way you would expect.
Secondary characters aren't all that great to be honest,the players are quite one dimensional and not very interesting varying from usual:the serious captain who gives all he has on the field,the up and coming new star player who lacks the necessary courage,the arrogant but experienced player,the constantly angry one ..... you see in other sports related series.
Most of them do get their own moment in which they shine on the field and get a bit of character progression,but overall they don't leave a huge impression as you would expect.
This also goes for the opposing players,some stand out more than the others but again there are no noteworthy mentions .Its clear that the author spent more time and effort in fleshing out the managers of the teams rather than the players.
Animation wise the series sufferers quite a bit.Up close the characters look decent for the most part and its nice to see that Studio DEEN tried to recreate the art style from the manga.
However when the camera goes further away for a "birds eye view" the anime switches to a very awful 3D CGI rendering of the players and the crowd.And its very poorly done ,the very basic way they look and move is nothing short-worthy of something you would expect a novice 3D rendering artist to produce.It simply looks awful and downright disgraceful for something made in 2010.
Also a lot of moments are single non animated panels taken directly from the manga and colored ,again something very cheap for a producer to do that you would expect from old series made in the 80's and 90's.
Sound is also nothing to special .The voice actors do their job ok-ish with no noteworthy performance and the very few dramatic songs are overly used and wear off their welcome very quickly.
The salvation comes from the sounds of the crowds during matches,the way they cheer on and sing for their supporting team is very well done and does manage to take you to the unique atmosphere you experience in a real life stadium.
But how does the anime fair compared to other sport related series?
Does it go for a realistic approach on football or does it go for a cartoony,over the top way like in Captain Tsubasa ?
Well the answer is the first type ,but not as realistic as you would expect.Firstly during the entire series they don't ever mention what kind of formation the team is using (its a 4-5-1 type,a very defensive formation) which they changed only once.
Also a lot of real life and very common in game situations such as: free kicks,faults,offside only happen one single time during the entire run.That's extremely hard to swallow for a series that takes pride in its realistic approach.
Others never happen at all :hands, simulations,penalty shots.All just completely disregarded.
Its a very lite take on football,a very movie-esque disregard for real life situations in order to keep the action non-repetitive and not backtrack to something that already happened.
Overall Giant Killing is a good series,but in can be a mixed bag depending on your expectations.If you're expecting a over the top sports anime like Captain Tsubasa or Kuroko no Basket you will probably be disappointed and bored.
If you're expecting a realistic take on the most popular sport on Earth in anime format you will surely like it,but will probably feel a slight disappointment for the liberties it takes at times,but it can be avoided as long as you suspend your disbelief in order to fully appreciate it.
