Cliched fun, but fun nonetheless. Some books we read not for learning or profundity but plain old feel-good entertainment. On that score Kings of the Wyld has done its job and done it well. Being a debut novel we can forgive the lack of polish, because the idea is there and it's a good start. I like that despite it being obviously the start of a series, the ending is nicely closed up with a cliffhanger for the next. The characters are not well-developed yet, but again, this is the first novel. 
 (view spoiler)[I just hope Ginny doesn't turn into another Valery. This pacifist-mummy stereotype who kill their kid's warrior talents is really an ugly situation. That's how you get Obscurials, people. (hide spoiler)] 
 This would make a great summer film if they can solve the daeva.