Summary
Sonic Generations saw the return of many fan-favorite levels, and the return of fan-favorite music. The majority of the OST is remixes, which are great, but I can't give as much points for originality. The cutscene music is lame except for one or two tracks (or lame compared to other games, at least).
As for the mixes, there is a lot of range. It shows how Sonic music has evolved. Classic has fun beats with some Genesis inspiration but it's much cleaner and there are less limitations. For Mod, the music gets richer with clearer instruments and it diverging more from the source. Some of the unlockable music was also remixed.
Surprisingly even the mixes I expected to find tiresome (Greenhill, etc) seemed fresh, though there were some tracks that weren't as good.
Best Song: Crisis City Act 1
Runner-Up (s): Crisis City Act 2, hub, Radical Highway Act 1/2, Speed Highway Act 1/2, Hub, Green Hill Act 1/2/hub, Chemical Plant Act 1, Tropical Resort Act 2, Emerald Coast Act 2, Rooftop Run Act 2, Casino Night Hub, City Escape hub, Metal Sonic Hub, Vs Metal (US), Big Arms, Mission 3, Skill Shop, Toxic Caves, Hyrdocity, Flying Battery
Crisis City is awesome to begin with, but they put a lot into this "Classic" version. The guitar, bongos, and 16-bit like synth fits the tune perfectly and gives it an almost Marble Zone (lava-dungeon) feeling. Just right for a stage that trolls the player with a goal post.
Worst Song: Time Eater: Final Attack
Runner Up (s): Title, Results 1/2, Cutscene 2 Cutscene 5, Cutscene 10, pretty much all cutscenes save 8, Sky Sanctuary Act 1/2, hub, Rooftop Run Act 1, Water Palace Act 1, Planet Wisp Act 2, Pink Spikes, Orange Rocket, Planet Wisp Hub, General Hub, Mission 5, Vector Beats, Marble Garden, Leaf Forest, Door into Summer 3DS Ver
WHAT THE FxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxCK?!!!!!!!!!!!!!!
A hint of "Live and Learn" dashed away by the disgustingly ugly theme of SONIC 4?! WHAT THE FxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxCK?!!!!! The even the horrible quality theme of Sonic Chronicles would have been better. It's trying so so hard to be Genesis music, but why? If respect for the past is what they were going for, they should have played the original invincible theme (or this games' invincible theme). Sonic 4 was pretty new at back then, but this is just wrong. Even "Reach for the Stars," which I. CAN'T. STAND. would have at least made more sense.
NOTE: Sonic Gen doesn't have a vocal main theme or closing theme like most console games, but since there are so many lyrical tracks, I'll go over those (just remixes made for the game, not unlockables or short versions):
Best Vocal Song: Open Your Heart (Crush 40 vs Circuit Freq RMX) (Vs Perfect Chaos pt 1)
Runner-Up (s): Supporting Me (Biolizard), For True Story (Vs Shadow), Escape from the City (City Escape) Act 2, Back 2 Back Act 2
A lot of the tracks struggle with the balance of change. Making it too different risks losing some of the nostalgia factor or the original vibe. But not changing it enough leaves it as a generic version of the "real version."
Of these, "Open Your Heart" is the only one that truly fits the balance...perfect? This is a cooled, calmer version yet it does not lose the edge or seriousness and can be quite catchy despite it's slower speed and quieter tone.
Worst Vocal Song: Super Sonic Racing Cash Cash vs Jun Senoue (OST Version)
Runner Up (s): Super Sonic Racing (game ver), Escape from the City (City Escape) Act 1, Back 2 Back Act 1
Not going to lie, this is catchy. Not bad, but silly. It's a pop-ish, 2010s-ish version of "Super Sonic Racing" from Sonic R, and it's just...kind of funny for some reason.
Final Ranking: B
Sonic Generations is a bit of a cheat since most of it's music is not entirely its own, but making mixes that capture the same essence without being a complete copy is not small feat. There is plenty of nostalgia to go around, and they did not slack with the 3DS tracks either.
Still, the game would have been cooler with a main theme. Some of the songs are very cool, but others feel too similar to their source or too modernized. It's fun for any Sonic fan, but not at the same level as other titles.