I'm a huge fan of both Star Fox 64, and Star Fox Adventures, and when Star Fox Assault was released, I was incredibly disappointed, I guess I was expecting more?
I thought up this concept of perfectly combining these games, not sure this would fit on a Wii U disc to be honest, but here's the block of text I wrote (I just posted this on another site, I won't be advertising it here though) I would just like to see what people think of this, maybe Nintendo can see this some day and get some ideas? 
Title: Star Fox Universe
Gameplay:
The game takes place in the Lylat system, a free-roaming fictional Universe first seen in Star Fox 64. Players can explore the vast Lylat system in an Arwing, encountering epic space battles, hidden upgrades, and many planets inhabited by ferocious enemies. Many new aspects are present, such as a real-time fuel system, players will have one hour of flight time before having to visit the 'Great Fox' to re-supply. Upgrades can also be unlocked to gain additional fuel time. Enemies are randomly spawned throughout the Lylat system, when killed, offer experience points, occasional repair orbs, as well as limited-time weapon upgrades.
The player will suffer a penalty when running out of fuel, losing any limited-time upgrades, and all experience gained while in flight, the player will then respawn on Great Fox, which can be seen slowly orbiting the Lylat system. The game utilizes an auto-save feature, which will take effect when passing a checkpoint, completing a mission or quest, landing on Great Fox or a planet, or defeating a boss. Fuel orbs can be obtained on planets, if you seek to land on a planet with low fuel, this will allow a player to re-fuel the Arwing before leaving a planet.
Planets:
The game will feature 15 unique planets of varying difficulty, Fox must be of a specific level to land on them. These planets are all ground based and once on a planet, Fox will not be able to use the Arwing unless to leave the planet. Optionally, these planets can be orbited (read below) Much like Star Fox Adventures, a previous game in the series, these planets will contain many side-quests, unique enemies, both common and rare item upgrades, and epic boss battles. Some planets will allow the player to use the Landmaster, and Blue-Marine vehicles to some degree.
Each planet will feature an orbit system, in which the player can choose to enter, rather than landing on the planet itself, players will circle the planet, defeating enemies for additional experience until all enemies have been defeated. The player can only gain experience one time on each of the planets orbit, and once Fox reaches a specific level, these enemies will no longer grant experience, however, the player will be able to return at any time as these enemies will respawn once leaving the orbit. These orbits will resemble classic levels first seen in "Star Fox 64", and will feature traditional on-rail gameplay. They will also feature high scores and time record keeping.
Once Fox reaches the maximum level, the final planet, Venom will be unlocked. Fox must defeat Andross' minions here, eventually causing Andross to flee the planet, leading to the most epic battle in space Fox has ever seen.
Corneria:
The home of Star Fox and friends, Corneria will act as a safe-zone planet, in which Corneria City is built upon, Fox can land here to interact with fellow Cornerian's, gathering quests, gaining additional armor and upgrades for both land and flight missions (based on level), which include learning new melee attacks, laser upgrades, and faster Arwing speed boosts.
When the game has been completed, a much more difficult 'heroic' mode will become available.
Online Multiplayer:
The game features two multiplayer modes, a co-operative adventure mode, and a deathmatch mode, both on land and in space, item upgrades and experience earned in the single-player campaign will be present in these online modes.
The game would also have some sort of offline multiplayer.
The series got rebooted in starfox 64 3d & tanked in sales bad.
