I played Codenames Duet once at PAX East 2017 with CGE's Joshua Githens, and the game presents an interesting challenge, especially since three of the spies are shared among the pair of you. This makes it impossible for you to guess only those words that don't show on your side of the card, yet you don't know which three are shared, so you're then considering everything on the board when given a clue — which is as it should be. (One word of advice: Just try to remember when you do identify a spy that's also part of your "half" of the team since that will help you narrow down choices in the future.)
During play, you're both staring at the board and either of you can yell out a clue and a number, but since each of you has spies unique to your side, you can't only throw or receive; you need to do both. Sometimes, though, you're happy for the other player to give a clue as the answers might eliminate something troublesome with a clue that you wanted to give — which mimics the nature of the original Codenames.
As Josh mentions in the video, CGE is still working on the timing mechanism at this stage of their development. We played with a stack of green "found spy" tiles, along with a row of individual spy tiles. When you gave a clue, you'd pick up the stack, cover any spies guessed correctly, then place the rest of the stack on the first individual tile of the row (thus increasing the size of the stack by one). If you need to place the stack back down but no individual spies remain, then you've run out of time and you lose; if you ever place the final tile in the stack and have nothing to put back down, then you win immediately (as the gamemakers presume that you're smart enough to guess any remaining spies on a 1-1 basis at worst).
• At GTS 2017, CMON Limited announced that it had brought on designer Eric M. Lang full-time as Director of Game Design as of April 1, 2017, and we spoke with him at the show about his responsibilities for the publisher and what this entails for future designs from him. Rising Sun was on the table, so we talked about that a bit as well.
• Lang then stuck around in the BGG booth to preview The Godfather: Corleone's Empire, which will be released in July 2017, presumably to avoid the money crunch that gamers will experience at Gen Con 2017. We actually recorded an overview of this game at GTS 2016, but now the design and components are final, so you can see the game as it will hit the market.
• And there was still more from CMON Limited as Lang and Jared Miller stuck around to present an overview of plans for Michael Shinall's A Song of Ice & Fire: Tabletop Miniatures Game, part of which will launch on Kickstarter in Q3 2017 and much of which will unwind in monthly batches once the initial starter set hits the market in 2018.