From what I skimmed of the script that was uploaded and having not played the leaked builds it seemed pretty cool on its own feet before Star Fox was slapped on.
Then again an interview from 2002 of the Star Fox director said that the franchise was going to have Fox McCloud having on-foot adventures anyway and Dinosaur Planet was being developed so it was perfect for them to slap the Star Fox name on it.
<Moving on from the N64 game to the Gamecube game, why did you decide to establish an eight-year time-skip?
>Star Fox Adventures originated here in Kyoto: personally, I’ve been working on the series for a long time and am quite attached to it, so I went to Miyamoto like, “let me do it! let me do it!” and he replied with, “for this game, why not try an adventure-style game instead of a shooting game?”, and so Morita and I began toying around with various ideas.
<What kind of game were you attempting to make, exactly?
>Something where Fox runs around on foot, taking out enemies with his gun, but shooting games with the character displayed with that behind-the-back perspective can be tough to play, can’t they? You can’t always see the enemies because the player-character’s blocking your view, right in the middle of the screen. I was aware of these issues, but I really wanted to realize Fox fighting with a gun, so I continued pondering directions for the game to take. In the N64 game, there are those stages with the Landmaster—the tank—where the camera automates itself and enemies pour in from the sky, right?
<So, you decided to take your Star Fox Adventures concepts and merge them into a game Rare was working on, Dinosaur Planet.
>That’s right. Dinosaur Planet was also being made for N64 in the beginning, but it was fairly late in the N64’s life product cycle and people were already talking about Dolphin, and as we were asking ourselves whether to go ahead with our project internally, the staff were already being pulled away to work on big projects like Mario and Zelda, and so after work wrapped up on Majora’s Mask, the project was restructured.
My same sentiments on the matter.
It was indeed a rushed game but to be a bit fair Microsoft purchased Rare around that period and any additional time that may have been needed to flesh out the story and polish the game were out the window.