That was a great episode. The stuff with King Shark was a lot of fun, and it was a nice way to bring Dig and Lila over to Flash.
It was nice that Cisco, Barry and Wells' visit to Earth 2 had some lasting effects on them. They got me when Caitlin pretended to be Killer Frost, for a second I thought she actually had taken her place.
I do have to agree with Christopher's early comment about the characters keeping secrets. They all agreed to keep what happened on Earth 2 a secret, but then told everybody anyways. I have to wonder why they even bothered trying to keep it a secret.
The act of revealing of Zoom was a big surprise, but after the last episode and the theories on here his identity wasn't. I am kind of confused though, because in the EW interview it sounded they said it was Hunter Zolomon from Earth 1, but then he was talking about him working with Team Flash. Everything in the episodes seemed to indicate they were actually working with Earth 2 Jay, and we saw Zoom carrying the dead body of a Jay, so that seems to indicate they are two different individuals. So how can Zoom and the Jay they were working with be two different individuals, but yet Zoom's identity meant the group was being betrayed? Were they working together and switching places?
EDIT:
If Jay is working with Zoom/Hunter, then maybe he faked the results.