Star Fox: Assault was first announced on May 8, 2002. It had a tentative release date of April 2003 for Japan, and would be developed by the same employees who worked on Ace Combat 04: Shattered Skies at Namco. New information about the game didn’t show up until a short video montage at 2003’s E3 in Los Angeles, which showcased the game’s first-person perspective.
During development, the game had three working titles: Star Fox Armada, Star Fox 2, and Star Fox. It eventually came to be known as Star Fox: Assault. [Infos from Wikipedia]
In 2003, the game was intended to be multiplayer oriented and was rumored to have a LAN mode too, but sadly it never did. If you play the game you can almost feel that there is more content in the multiplayer mode, with more stuff to unlock. Most of the missions in the single player are the same arenas used in multiplayer, with a touch of story. There was going to be a coop-mode for the Adventure mode, but sadly it was cut.
In these screens and video, we can see an early version of the game, with inferior graphic, Aparoids from level 9 seen in level 2, different text, slightly different character design and HUD. It’s interesting to notice that the Star Fox Armada Project was going to have an arcade version too, as it happened with F-Zero GX. The arcade version of Armada was never released and we can only wonder which kind of differences it could had.
Also a Unused Game Over music has been found by Gabrielwoj, it is the same Game Over Music of Star Fox 64, see video below!
Update: New video of the E3 Trailer (the other one was deleted, enjoy this one)
Thanks to bydolord and Gabrielwoj for the contribution!