This episode only works because Grodd is in it, and I'm still thrilled by the fact that we get to see Gorilla Grodd on live action TV. The central storyline, ostensibly, is Grodd coming to terms wih his existence by, um, trying to create a race of superintelligent gorillas with Caitlyn's help. So about par for the course there, really. Grodd and Caitlyn get some nice King Kong/Fay Ray moments. Added into this is Harrison-2 pretending to to be Harrison-1 to fool Grodd into behaving himself, which, unsurprisingly, doesn't work.
The other side of the episode sees Barry getting over his crippling injury by Zoom the episode before. While I never expected Barry's paralysis to be permanent, I'd have thought they'd at least have him grounded for a few episodes while he healed, emotionally and physically. I get that this is a metaphor for his regaining confidence after his defeat, and it works well as that, but it's still over too quickly to really accept. His dad drops in as well to give him a boost, and gives an actual reason for leaving town as soon as he got out of prison: he can't stand to live in a place full of people who saw him as a murderer. Which is understandable, but it's still bizarre to have him skip out on his son like that.
However, there are some great moments for Barry-Patty and Cisco-Kendra, Harrison-2 is still very much a highlight of the series, and it ends with a gorilla being punched into another dimension. Which is something that deserves a place in anyone's viewing schedule.
LEGENDS OF TODAY/LEGENDS OF YESTERDAY
In case the title didn't make it clear, this two-part story - which crosses over between The Flash and Arrow - exists almost solely to set up Legends of Tomorrow. However, it does manage to spend some time on some rather lovely character moments, particularly between Oliver and Felicity, and move on the ongoing plot of both shows (a little of Speedy's development, a crisis for Patty, Jay, Caitlyn and Harrison-2). It's a good thing I've been following Arrow more this year, because it would be pretty confusing coming into that series' side of things otherwise. That said, the most important part of that series' story, the relationship between Oliver and Felicity and the revelation the former has a son, is easy to grasp for more casual viewers.
Mostly, though, this is about introducing the really out there characters due to make up part of the Legends team, namely Kendra/Hawkgirl, Carter/Hawkman, and Vandal Savage. Throwing in a pair of eternal lovers from ancient Egypt, reincarnated again and again over thousands of years, and the immortal warrior who hunts them down, takes the Arrowverse to new levels of comicbook weirdness, but to their credit the showrunners pull it all off. This is overblown, overexcited nonsense, with way too much breathily delivered exposition and some really crass dialogue, a huge rewrite late on due to the power of time travel and some rather fudged action scenes. But god, I enjoyed this.
Cisco and Wells remain probably the best things in The Flash, so it's a shame they don't interact in this story, but they both have more important things going on. I was a bit disappointed in Caspar Crump as Vandal Savage; he looks the part but his performance was a little underwhelming. (Zoom would kick his arse.) John Barrowman is still terrible as Merlyn.