I think it's okay, not good. You just have to watch it and not expect greatness. Kind of like The Strain, though Gotham isn't falling into as many pitfalls as The Strain is. Either way, worth some entertainment when nothing else is on. Gotham is a cool idea, and it may get better.
The problem is that the bar for TV shows has been raised very high by shows like Breaking Bad, True Detective, The Walking Dead, Hannibal, The Leftovers, Game of Thrones, Fargo, etc. There's really nothing (save Hannibal) on regular network TV (like, NBC, ABC, FOX, whatever) that can compete. The production quality is just not great.. acting is iffy.. I think scripts and stories are written to appeal to a wide audience that doesn't want to invest any time into a television show.
Watching the pilot episode of Breaking Bad feels like you're really involved in something. Watching the pilot of Gotham felt like.. "well, I can go cook some dinner while I'm watching this". Nothing invested... no real risk of missing anything.
I felt similar when I watched the first episode of Gracepoint. I found myself checking my phone, doing other stuff, not really getting engrossed in the television. Compare to The Killing (which has almost an identical premise), where I was immediately interested in what was happening and why, who these people were and what motivated them, etc. I'm hoping Gracepoint picks up.
Speaking of television shows: It was announced yesterday that Twin Peaks is getting a revival in 2016 on Showtime. It will take place in current time (~25 years after the events of the original series.) Twin Peaks was, I think, one of the best and most innovative television shows around.
A link: http://qz.com/277156/how-and-why-showtime-resurrected-twin-peaks/