STAR FOX 64 3D PLATINUM SOUNDTRACK was released on December 26, 2011. Redeemable to Platinum members of Club Nintendo in Japan. The soundtrack is composed by Koji Kondo, Hajime Wakai and Satomi Terui(also arranger). The Star Fox 64 3D Platinum soundtrack consists of 42 tracks, compared to the Star Fox 64 Original Soundtrack which has 39 tracks. The tracks on the 3DS version aren't necessarily new, they just have a more polished sound to them—as you would expect. So, the track flow is the same as the original but with more orchestral as opposed to a synthesized sound of the original Star Fox 64.
There are some used copies on ebay going from $60-90 if you're looking for a physical disc but STAR FOX 64 3D PLATINUM SOUNDTRACK is uploaded in both FLAC and MP3. Enjoy!