Jamestown is an old-school Shoot-Em-Up (SHMUP) game, played with up to four players cooperatively. Each ship has a normal "vulcan" cannon, and a special ability that slows them down, but is (generally) more powerful. Collecting gears fills your Vaunt Meter. When that's full, you can activate vaunt, which clears all bullets around you for a moment, and then gives a significant damage bonus as long as it's active (and it can be prolongued by collecting gears).
The original Jamestown was released for PC/OSX/Linux a few years ago, and the developers (Final Form) had decided to create an expansion. I was hired to work on Jamestown+ as a programming contractor. Final Form had agreed to launch J+ as part of Sony's Spring Fever event in 2015, and needed some extra muscle to finish the project on time. I had just finished launching Splice on PS3 and PS4, and the recent experience with Sony's requirements and pipeline was valuable to them as well. My primary tasks were new UI implementations, performance improvements, and making sure that technical requirements were met.