Pros
It was great to work for Amazon, we had the unique chance to develop a brand new game from scratch and ship it on all platforms, console and PC. It was a great time to join as there was a lot of stuff to build, a new studio, a new team, a new game. Shipping the first game for Amazon was very challenging but rewarding. I joined for the salary but stayed for the team. In the end, we had some successes, a lot of failures we learned from, maybe not fast enough.
Cons
Amazon not being a game studio, it came with some challenges. The time it takes to develop a game doesn't align very well with how Amazon operates. Ultimately, Amazon decided to shut down their game studios, most likely due to being a business that was not making any money, with no prospect to make any any time soon. People hired at the very beginning to build the game studio division made poor choices investing money in building an engine, versus using Unreal and make games. The people that made this decision did not know much about the game dev business.