Everything was there... yes, cliche and fan service too -_-
Everyone just looks at the clicheness and judged it.
Take a look again in absence of the cliche. <----
It's better than many if not good.
Story:
It has everything a story needs and is definitely solid. It has conflict, climax, and a very good resolution.
There's easily 3+ conflicts well mixed with a climax building on top of each other and ends closing up the instability within and outside the group.
People should get past the "I don't know so I don't like" mindset etc. This story without a "backstory" and "development" did a better job than those with an open ending and draggingly long stories imo. Not everything needs an explaination. That's what makes this different. (See next paragraph) It doesn't drag on like a b*!$*! explaining, backstorying, flashbacking like crazy. Sure those are good, but not in everything all the time. Lets be honest, this is better than your normal action movie... obviously not as realistic though.
For those that don't finish the anime and say everything is unexplained with no character development obviously never finished the anime. Those get answered and developed along the story and come together at the end.
Characters:
By the way, the intro should give you enough backstory anyway and the backstories of most characters were shown.
The haters that say there's no development just hate the cliche characters, there's definitely character development.
I don't hate cliche/unoriginal stuff, but rather just dislike them.
In the end characters were more closer, feelings told, mysteries revealed, and friendships renewed.
The characters individual development were very solid and improving in character without drastically changing the core characteristics. That's better than a character who changes what he/she is on a whim because it appeals better. This was more solid than more popular.
Art:
Too many people are salty.
Forget all the cliche and story and look at just the art. It's not amazing, but neither is it absolute crap. Get ahold of yourselves people, because you hated the stories and characters so much doesn't make the art absolute garbage.
Saying the art in this sucks destroys many popular anime too, chill.
In the end I enjoyed this more than many other anime believe it or not, tonnes more than Steins;Gate for example. (Ready for the hate)
But don't get me wrong, this anime annoyed me too with character unrealistic stupidity and stubbornness. But then again, this is more of a "throw me some action less story, idc if it's cliche" anime/movie/series which many people enjoy. (Obviously not many in MAL or anime)
In many aspects this is a better anime than many imo, it's just cliche with action that you don't have to figure out.
Chill people.
If you're looking for my score on this, it's overall a 7ish all lost to clicheness and other minor things.
It's better nailing a cliche movie/series etc. than trying to be interesting and turning "meh" (Still try different things though)
Extra bit:
Should end here. I don't usually say that as I usually want more, but the anime wrapped up nicely so I don't see a point in a S2.