It was just as bad as every crossover episode. The show gets neutered for an episode. It was cute and lite and kind of fun. Cat Grant was thankfully consistently great. Nice knock at the CW too. Amazed that Martian Manhunter wasn't even in this episode at all. Do they save money per episode by not including everybody?
The race should have been a lot longer and more fun! Craptacular ending. I wanted to see them race over land, mountains, rivers, and the ocean before he warped back. Silly me.
I realize it is pointless to apply physics or rules to a superhero show crossing over with another, but ... Barry ends up on "Earth-3" shall we call it, for the first time, and even though he probably left Central City, which exists on this Earth, he BAMF!'s to this Earth's National city right as Supergirl, the heroine, is thrown out a window, and catches her.
And everybody just loves each other. This is the lightest of all entertainment. Where is the dark , the stormy rain, the CGI destruction? *
* just poking fun, I still enjoyed it for what it was.