It might have its faults, but it's still good.
Starfox Assault takes place about a year after the events of Adventures. Fox and company are put back into action to stop a new threat to the Lylat system. At first, this seems like Andross' nephew Andrew and the remnants of the Venom army, but instead, they are the insect-like Aparoids, whose ways compare to the Borg of Star Trek. Those who are captured by the Aparoids are assimilated and one single Aparoid can take down a whole fleet with little effort. It is now up to Fox and company to stop the Lylat system's new threat.
The main part of the game revolves around the concept that made the first two games of the series instant classics, flying around in space. Fox returns to the Arwing where he belongs. However, he will return to his Adventures roots by doing a few land missions. Here's where the game kind of starts to show its faults. While the controls of the flying stages are perfect, the land missions are a little faulty in control. Shooting's okay, but how you control Fox is kind of broken. Like Adventures, the graphics are excellent, and can almost remind you of Star Trek.
The game, of course, is known for its single player mode. However, a multiplayer mode is also offered. It might be fine for a bit, but after a while, it gets rather boring.
This game's not bad, but I wouldn't compare this to the other games in the series.