Fun fact: this game was made two times and released zero times.
Sync was originally planned to have no story and take place in one large sandbox style world. However, due to the limitation of the grappling system, a story was added and the world was split up into smaller areas.
When the original prototype was created, Sync featured a combat heavy gameplay system. This was later removed to favor the addition of a story and breaking up the world into smaller sections. While remnants of the combat still exists, the game evolved puzzle solving elements with the original weapon used as a tool.
The working title was GRAPPLE, due to the game originally featuring a grappling hook system. The feature still exists in the game, however it is limited to offer a more cinematic gameplay experience.