You may be thinking to yourself, "Yeah son, I love Sega Tunes." I'm here to tell you that what you are thinking now may in fact not be what you will be thinking. That's because Sega Tunes isn't typically what you or I envision when we think of Sega tunes. See, during the 90s, Sega put together covers of game music and (supposedly) sold them on compact discs. Let's Listen to some samples.
X-Men 2: Clone Wars
This here's the original version of the Brood Queen track. Immediately, the hard-hitting (almost resounding) percussion introduces itself. You've also got a gritty background track which is kind of your bassline. It serves pretty much the same purpose as a bassline, anyway, giving a simple melody to lend the song character without stealing the show from the lead. Anyway, around 0:27, your siren-like lead instrument blairs in long, rarely broken phrases to juxtapose against that gritty background thing.
At this point, you know all you need to about the Brood Queen. Don't pay too close attention to any individual phrase; it's more about the instrumentation than anything, contrasting elements on basic levels. Any time I genuinely listen to the lead melody, I find myself a little frustrated--it's just messing around. You'll run across a breakdown here and there, but nothing comes together beyond the notion that these sounds are pretty cool when they're next to each other.
That's not to say X-Men 2 is without interesting bits. Avalon 3 takes on a lurching flavor that I don't think any other Genesis track manages to hit with as much quality.
Sega Tunes pretty effectively makes itself irrelevant here
by softening up on the percussion and providing a bassline with a quarter of the grit (I measured it in a vial and everything). I'm tempted to say the background melody is less scratchy, but I think there's something more to it, as well.
It's not all bad; the higher production quality brings out key instruments above others, while the Genesis original can be a heap of sounds at times. In all, though, Sega Tunes softens the blow and misses the point.
The entire Comix Zone soundtrack takes on a 90s grunge feel. It makes a lot of sense, but I wouldn't have guessed that the Genesis sound chip could produce such a loyal grunge guitar synths; certainly not ones you'd honestly confuse for real instruments, but synths that capture that spirit all the same. A modest square synth takes over vocals, but--well, similar to the Brood Queen--a simplistic lead instrument succeeds in tying together more elaborate backing elements.
And beyond that, the structure and melody are convincingly grungy. The melancholy yet poppy melodies strike a tone too subtle for most games of the time. As for structure, the instruments have a strong interplay; there's no such thing as "the interesting track" and "the mood-setting track." This results in a soundtrack that rewards relistens more than most of its era. While only one or two tracks will take the limelight at a time, each one (percussion aside) is always busy doing something worthwhile.
Here's the Sega Tunes version of that same song. All of your wildest grunge fantasies are brought to life as Sega forms a band with real instruments and a vocalist to transmogrify your 16 bit nonsense into real music.
Take the passage at 0:40 in the Sega Tunes version and 0:22 in the original. In the Sega Tunes take, everything gets lost in the mire of a heavy guitar, with the vocalist reaching out. (For a quieter bit with more contrast, look to 1:21.) On the other hand, the original Genesis version still provides a satisfying heavy metal guitar, but it also keeps every other sound discrete and audible.
This is where your taste comes to bear. On one hand, dense heavy guitars are half the point of grunge; it's a mire for a reason. On the other hand, I can't deny the appeal of something more listenable, especially if it's going to highlight a series of instruments working together.
There are plenty of other Sega Tunes albums, too. Some (Virtual Sonic) are more interesting than others (Toejam & Earl), but they're all worth checking out, if only to see how Sega reinterpreted its game soundtracks.