I haven't had cable in forever ever, so I missed this until I found it on netflix. Reminds me that syfy can turn out something occasionally that isn't B grade or lower.
The actors playing the characters felt familiar to me, I tend to pause when that happens and see what they played in on IMDB to get that out of the way so i'm not thinking about it the whole time. But it didn't turn out that I had known them, perhaps their characters or the way they were presented, hairstyles, personalities just felt familiar. That helps draw you in if you feel connected to the characters.
Some mentioned some natural similar themes to narnia and harry potter are baked in and if you enjoy those then that will help you as well. One of my favorite book series WOT uses lord of the rings and king arthur and atlantis and dune and just about everything in myth and history that it feels like and wraps it into its story, so i'm never one to care where u get your ideas, its more how you use them and make them your own.
One thing this does well for me is style of humor. I never like comedies because I require very specific types of humor other wise i'm just not interested, and this one is perfect for me. Also the 4th wall stuff is funny. Its usually considered inproper to be self referencial, but that was long ago, people keep trying it. Where a show is aware its a show and talks about itself to the audience as if they know there is an audience. :P They do it alot in this show. The characters often will talk about themselves as characters or plotpoints as plotpoints, which of them are the main characters or side characters. etcetera. It works for me the way they do it.
I've never been afraid of LGBQA etc people or characters. I really like Elliot, and the Elliot + Margo duo dynamic. I also like what they did with Dean Foggs personality. He is perfect. Id never thought to create him the way they did. I'm curious if the book has this as his personality. I like how he is self aware too. I've had a high shool teacher or two and a college teacher that had been teachers too long and just need drugs or alchohol to make it through the day. One said I don't give A's because no one is perfect and none of you are likely to change my mind on that, B is my best grade so i'm going to reserve it, C is the highest your all likely to see but u'll have to earn it. That was first sentence day one. It was all downhill from there. Dean Fogg fits in really well with that teacher of mine. Whoever wrote him did well.
Basically the writers did well. On personalities, and humor, 4th wall self awareness. There are many things done intentionally to create drama and to move the story along. Things that should perhaps be easy that are hard and that should be hard but are easy. I don't mind. If you like characters who are drawn well u go along with whatever they get put through. As for 5 seasons. Something cannot go on forever. have to draw the line somewhere or it wears out its welcome. Haven't finished it yet. Hope they can stick the landing. Many thing are a great journey with good people, to a bad destination.