Larry Holland’s Totally Games, the studio behind a slew of well-regarded flight simulators often published by LucasArts (among them the X-Wing series), was at work on an Xbox-exclusive fantasy game in the early 2000s that didn’t make it to the finish line. Details on the sometimes-called Knights of Decayden have now emerged from Axios. Here’s a summation by Eurogamer:
According to Axios, Knights of Decayden - which has briefly surfaced once before in 2009, in a listing on cancelled games website Unseen64 - was to take Totally Games' experience with space shooters and adapt the formula to suit a fantasy setting. It would see players - either in the single-player story campaign or multiplayer mode - controlling a knight on a flying seahorse, travelling "amid skyscraper-like islands soaring above a sparkling sea." Action was to be a mix of ranged combat and slow-motion jousting against other knights and monsters, and would also incorporate underwater segments against sea creatures.
In addition to reading about how the game died, you can check out this footage: