With a lighter vibe and toned-down violence, this spin-off of fellow CW superhero show Arrow is suitable for younger viewers (and an easier sell to worried parents, too). Gustin appeared briefly in Arrow as Barry's alter-ego role as a crime-scene investigator, and Stephen Amell's Oliver Queen shows up in a few Flash episodes, too. The crossover between the two shows -- and the mentor/student relationship between the two heroes -- is tailor-made for Arrow fans, to be sure, but you don't have to know that backstory to fall in step with this one. What you do need is an appreciative imagination and a soft spot for a slightly awkward hero, more along the lines of bespectacled Clark Kent than the self-assured likes of a Bruce Wayne, for example. Barry adjusts to his new superpowers far more quickly than he does to the duality of his two identities, and masking his second identity further complicates matters with Iris, his longed-for love interest who's involved with someone else but soon becomes obsessed with the town's unidentified new superhero (and, in later seasons, becomes the pivot-point for a plotline that endangers Barry and those close to him).
That said, Barry's insecurities make him really likable and cause him to wrestle with matters others in his place might disregard. At one point, he even voices his concerns to Arrow's Oliver (Stephen Amell), vowing that as much as he wants to embrace his new identity as a hero, he never wants to be a vigilante. It's a nice element of humanity that helps ground him, makes the line between right and wrong pleasantly clear for viewers, and keeps the content from delving too far into the darker side of heroism. Overall, this is a fun pick for those who love a good superhero tale, and good whole-family watching.