Vicarious Visions coined the term "Remaster Plus" to describe the collection, as they did not fully remake the original games, but rather used Naughty Dog's original level geometry to rebuild the gameplay from scratch. As the levels were coming together, they added their own art, animation, and audio. Almost none of the source codes for the original games were available to the developers, as the game engines were specially written for the original PlayStation and Vicarious Visions could not find a way to use it on more powerful systems. Sony and Naughty Dog were able to provide various polygon meshes from the original, although many important elements from these were missing and the team found that "they were compressed in some wacky format that we had to decode". Vicarious Visions looked at various internet communities to make sure they had essences of the games captured. The team had some fans test the game and give notes about it compared to the originals. In April 2017, there was a contest for fans to submit ideas for idle animations for the character, with the winners announced the following month.
