The general vibe of Schoolgirl Strikers is "what if someone made Yuki Yuna Is A Hero, but replaced all the sad parts with more scenes of the girls having wholesome fun together". That's not to say the series is entirely without drama, especially in the last few episodes, but it isn't anywhere close to as dark as modern magical girl series like Yuki Yuna or Madoka Magica. It's much more in line with classic magical girl shows where there are obstacles they need to overcome, but the good guys always win in the end and learn a valuable lesson about the power of friendship or whatever.
The drama and plot is generally the weakest part of the show in all honesty, it shines brightest when it's in slice of life comedy mode. Fortunately that's the vast majority of the show. It's never really laugh out loud funny, it's just got a lot of gentle humor that'll get you smiling and make you like the girls. There are a lot of fun bits throughout, like Mana becoming a yeti hunter or Odile's shoujo anime parody, that are just cute and nice, even if there aren't really any great jokes or anything you would describe as hilarious. There's not a lot of substance, but it's very pleasant to watch and the girls are all very likeable, including the side characters.
It's got plenty of flaws too however. The art and animation looks a bit cheap at times. The action scenes are pretty uninspired. The deus ex machina ending is bad and they barely even put up a pretense of attempting to explain why everything turned out fine in the end. The characters and themes are a bit childish ("learning valuable lessons about trusting your friends" is a theme that would be more suited to elementary schoolers rather than high school girls, and some of them act more like elementary school girls as well).
None of that is enough to make me dislike the series as a whole though. Overall I liked the characters a lot (Odile best girl) and it was a consistently nice watch that always made me chuckle and put me in a good mood. It may be uninspired or lacking substance in some people's eyes, but I never had a bad time watching it. Frankly speaking, it worked as an advertisement for the mobile game too because I wanted to check it out and spend some more time with the characters, only to find out that it isn't available in English. Oh well. Maybe some day.
