For people worried about the fanservice aspect:
Since this is the big topic in other reviews: I've been rewatching the first season with my friend and I can definitely agree that it begins with excessive fanservice within the first 8-10 episodes (probably ~12 fanservice instances) but this definitely dies down after they handle their first culprit. It becomes more fight oriented afterwards. Yeah, there will still be aspects of fanservice every now and then but if you like the story enough it's easy to look past it. And honestly? It's anime -- It does a stupid fanservice thing for maybe 5-10 seconds and then moves on with the story, it's not the end of the world. The story will continue to get more plot heavy soon with Season 2 this out summer and it gets much more interesting imo.
For people curious about the plot:
Yes, it does throw you in to the world from the get go, but what show take 5 minutes at the beginning to explain the plot to you? Only a few. Almost all shows throw the viewer in. You just have to be willing to actually keep up and figure stuff out with hints and/or answers the show provides. It's really not hard at all to follow, so I don't know why people were complaining about this in other reviews.
For me, the show has entertaining arcs and builds on characters as the story goes on. Granted, some of the building won't begin until season two where things are heating up but if you're interested in the show from the first season, then the wait is worth it. It's action oriented, and sticks to its plot goals, whatever they may be at the moment.
Overall, Fire Force is currently my favourite show because it feels unique and new among the other shows I've browsed through in the past. Each character has their own personality and design. There is no same face syndrome. The fighting scenes are complex, and the creators show how and why the characters are becoming stronger. They don't just magically get stronger which is nice. Additionally, each character has their own weakness which adds to the story. For example, Arthur's stupidity. Not everyone is OP which is nice to see.
Additionally, the voice actors in the sub fit their characters. The only one that throws me off a little is Licht. Because of this and the dramatic music that plays, I gave a 8.5/10. Almost all shows anymore rely on music to further the mood so I can't be too critical about it.