I loved this ep, it's probably the best Piplup ep I've seen so far (if memory serves me well).
I actually thought it was going to learn Brine rather than Hydro Pump, with Brine being a 4th gen move, I thought they would have wanted to showcase it more han Hydro Pump, a move we've seen many times over the years.
Gible was hilarious, I've really warmed to the little land shark. His constant chewing on anything was awesome, and although it did it a lot, it didn't feel overdone.
There were 2 little things that niggled at me though. First was Dawn using her pokedex, AGAIN, and on a pokemon she's already seen no less. I almsot expect her to use it on one of her own pokemon one day lol.
The second was the animation for DM looked a little odd to me. Maybe it's just me, but it descended a bit too slow to the ground (Piplup).
But that's just me nitpicking, I thoroughly enjoyed the ep, and am lookin forward to the next one.