Gotham is pretty batshit crazy, and they just kind of throw anything at the wall to see what sticks. There's some extremely jarring and misguided tonal shifts, loads of threads that are obviously just abandoned part way through because they had no idea what to do with them, and it has a really bad habit of most of the time when someone is killed, it just means that they'll be back with super powers or something in a few episodes time.
But I do really like it, it's got some incredible performances. Their take on Heart of Ice is great, the episode about the Red Hood is a nice little standalone story, and the kid they got playing a Young Joker is a lot of fun. On the whole I would say the production design is a league or two about other similar shows.
It's inconsistent as hell, but definitely worth watching for the highs. To some extent it got over it's identity crisis by the end of the second season, but not entirely.
It plays pretty fast and loose with continuity, where a bunch of the characters/events pulled from the Batman canon get reinvented. Sometimes to great success, but other times it's just a bit of a mess.
Main weakness imo is the dude playing Jim Gordon has a pretty limited acting range, and he's the least enjoyable guy from the main cast. A lot of the young Bruce Wayne stuff is weak, too.