It is rather long and I took a long time listening to songs and thinking about them. I have trouble putting what I feel into words for most of them, but I did my best.

I personally think Indi is one of the best game makers in the world when it comes to picking music. The music he chooses fits perfectly almost always. It is better than if he had hired the best in the music business to come up with custom music tracks. There are a lot of games with pretty music, but I still haven't found anyone to match Indi.

Hopefully there aren't many typos. I wish I could have done a more in-depth analysis but I didn't really have time, and I wouldn't have been able to express it right.
Okay, here it is:
Spoiler: show
Achaidh Cheide:
Kind of peppy. I don't remember all of the places Indi used it in the series, but I liked it in the towns.
Anonimus:
The way Indi used this surprised me. But it totally works! It seems he usually has this in rather disappointed parts that turn to happier emotions. I would have never thought of its use there.
Back to Space:
I didn't really care for this one much but it reminds me of Jack, and it isn't annoying +::grin
And it fit the place it was played in.
Beyond the Sky:
This one was really cool! It made me feel like there wasn't anything I couldn't do!
Caribian Party:
Hehe! Party song! I found this one kind of weird... so it was perfect when Indi used it in Mr. Clown's place!
Celtic Beats:
The battle theme for MM3 & MM4. I like this battle theme better than the one used in 1 and 2. It works for small battles and bigger battles. I hate it when game makers use an overly dramatic battle song for every battle. Indi NEVER does that. :DDD
Celtic Whispers:
Hmm, I don't remember this one. I'll have to replay MM4 to see when it was played. I might have had the volume off when it was played. I'll update when I see. But it is a very pretty song.
Chasing Thunder:
Battle theme for MM1 and MM2. I didn't care for this one too much (I wore it out trying to level up so I could fight Karanki!) but I liked it better than a lot of other battle themes. It is not over-dramatic.
Control:
My sister loves this one! It isn't used much but it is very fitting when it is.
Dancing Blinds:
Usually played in caves. I don't know why it works, but it does. It kind of sounds like it is somewhere far away.
Distressed Piano Duet:
For some reason I find this one amusing. Like hilariously over sad. But Indi slowed it down when he used it. I didn't laugh
then, IDK why.
Divine Feelings:
Oh, this one is so sad! I always have to fight tears when it is played. It always feels like either something is really sad, or so beautiful that it hurts.
Dreamland:
I think this was played in the title screen? IDK. Maybe not. Anyway, a very sleepy, peaceful song.
Drift Away:
What a perfect name! It was played in those snowy mountains when you were looking for Jezabel's griffin. (I don't remember the name of the mountains, LOL) It so worked perfectly there! I think it works nicely in any snowy, calm and quiet place. Or an airy lovely land. I miss this song.
El Gran Salto (Big Jump):
Played in the world map. I like this one a lot. It just feels right.
Electroney:
Played in almost all the temples. Pretty cool, kind of tech-y sounding song. It matches all the lights and gears and higher-tech things found in the temples.
Elysian Fields:
Very peaceful. It's like, "Hey man, all we really need is love!" LOL JK But really, it sounds like something to go along with a realization that would end up making everything better.
Epic Battle:
Played in orc land. Orc Fortress, actually. LOL Maybe one or two other places that I don't remember. Maybe not, though. Anyway... I didn't tire of it as long as I listened to it while in the orc place. And it fit well. I mean, the orcs could have been eating juicy James while we were looking for him!
Flying:
!!!!!
Played during really happy and surprising moments. Like when Jeanne came back. It made me feel really happy and like everything was going to be better (If it suddenly came on during a rather distressed moment. Like when you are about to be eaten by a dragon???)
Garden of Dreams:
Definitely has a fitting name. Played in the Forbidden Zone. I felt it as a almost slightly romantic song. It really did have a dreamy feeling.
God of the Forest:
Played in Chantfleur Woods and many places similar to the Woods. A really cool song. You'd expect elves and any number of other magical creatures to be spotted peeking from behind a tree when you hear this. Or, at least, I did. lol
Infiltration:
Creepy. But I like Chill Purpose's songs. Indi did a good job picking this out for when we had to hunt down the Rogue. It added to the already tense atmosphere of the swamp. THE ROGUE!!! *GASP!* lol
Kyoto Lounge:
HAHAHAHAHA!!!!! I LOL'd when I heard this played in Mystrock once you go into that castle building (ALRIGHT! I am horrible at remembering the names of places!) Waiting room music? Indi, you are really funny!
Love Loud Beam:
I LOVE THIS SONG!!!!!!!!!!! It is so peaceful and pretty and everything else nice! I'm so glad Indi uses it! It makes me think of a new morning when you are just waking up. Especially when it is played while you are at the Bear's house after failed tests. And it is just really peaceful. Perfect for those small towns. Also a rather romatic sounding song ("Love"Loud Beam?) I'm glad Indi uses it a lot.
Magic Harp:
So pretty! I like this one pretty much as much as Love Loud Beam. It is played in those grey mountains that I NEVER ever remember the name of! LOL! I think it would also work for any place with a lovely waterfall. The notes are sort of cascading.
Metalstorm:
Hmm, I HATE metal music, but this one is actually OK. Works for those battles where you really have to fight hard. It kind of grew on me. Not that I would choose to listen to it but it doesn't annoy me now.
Omen:
Interesting song. Played in the Monastery and cult of the Dragon. I don't exactly know how to describe it. But I do like it.
Patience:
!!! This is just so gorgeous!!! It couldn't be named anything else! It is a little like Magic Harp in the way that it reminds me of waterfalls in how it kind of just cascades. It also makes me think of rainbows and sparkles! Hehe~
Peanuts:
Ooh, this one kind of gives me a creepy crawly feeling. I don't like the loud bangs in it. Not one of my favorites. But it really goes nicely in some of the caves.
Pole Position:
Played in part of Shumen, I think. I like this song quite a bit. Also one of those songs I can't really say much about. But it is just LOVELY when Indi puts it in the game...
Right Behind You:
Now THIS got annoying! I don't know how many times I heard the really horrible noise in the beginning. But another song might not have worked as well. It really got that creepy feeling across to me as I was looking for Merline.
Road to Victory:
Eh... I don't like this one much. But I think Indi put it to good use.
Royal March:
Not my favorite for sure. It goes well for the moments it is played in, though. I just don't like marches much. Hehe!
Skyline:
This one is nice. It reminds me a little bit of Back to Space, but I think this one is better.
Snow:
This one is quite sad. It sounds like a struggle, to me. (An emotional one, of course. LOL) It always made me feel more for the person having a sad moment. I think the best use of it was when Jack was telling everyone about his werewolf problem. Though it was put to good use in several other moments.
Stargazing:
MM1 title screen music. Not much to say, except that it is pretty.
Suspect in Motion:
Eep! REALLY a creepy song! TRUST NO ONE! THEY ARE ALL OUT TO KILL YOU! LOL
Tales from Scotland:
Ugh! I'm hitting myself for not remembering when this was played! I only have faint memory of it... sometime really triumphant?
The Travel:
Hmm, I never thought I'd like this song so much, but I do. Played in Marine's home town.
the Worm:
An ugly song... but I like it. I don't know how to describe it. But now it makes me think of bugs! Especially spiders!
Twisted:
Creeeeeeeeeepy! That's all. CREEPY!
Under the Fig Tree:
Ohhh... it is so calm. So peaceful. It is very warm. A truly lovely and wonderful song.
Creep In:
Hehe! The name fits well! I don't remember where Indi used this, though.
Kind of peppy. I don't remember all of the places Indi used it in the series, but I liked it in the towns.
Anonimus:
The way Indi used this surprised me. But it totally works! It seems he usually has this in rather disappointed parts that turn to happier emotions. I would have never thought of its use there.
Back to Space:
I didn't really care for this one much but it reminds me of Jack, and it isn't annoying +::grin
And it fit the place it was played in.
Beyond the Sky:
This one was really cool! It made me feel like there wasn't anything I couldn't do!
Caribian Party:
Hehe! Party song! I found this one kind of weird... so it was perfect when Indi used it in Mr. Clown's place!
Celtic Beats:
The battle theme for MM3 & MM4. I like this battle theme better than the one used in 1 and 2. It works for small battles and bigger battles. I hate it when game makers use an overly dramatic battle song for every battle. Indi NEVER does that. :DDD
Celtic Whispers:
Hmm, I don't remember this one. I'll have to replay MM4 to see when it was played. I might have had the volume off when it was played. I'll update when I see. But it is a very pretty song.
Chasing Thunder:
Battle theme for MM1 and MM2. I didn't care for this one too much (I wore it out trying to level up so I could fight Karanki!) but I liked it better than a lot of other battle themes. It is not over-dramatic.
Control:
My sister loves this one! It isn't used much but it is very fitting when it is.
Dancing Blinds:
Usually played in caves. I don't know why it works, but it does. It kind of sounds like it is somewhere far away.
Distressed Piano Duet:
For some reason I find this one amusing. Like hilariously over sad. But Indi slowed it down when he used it. I didn't laugh
then, IDK why.

Divine Feelings:
Oh, this one is so sad! I always have to fight tears when it is played. It always feels like either something is really sad, or so beautiful that it hurts.
Dreamland:
I think this was played in the title screen? IDK. Maybe not. Anyway, a very sleepy, peaceful song.
Drift Away:
What a perfect name! It was played in those snowy mountains when you were looking for Jezabel's griffin. (I don't remember the name of the mountains, LOL) It so worked perfectly there! I think it works nicely in any snowy, calm and quiet place. Or an airy lovely land. I miss this song.

El Gran Salto (Big Jump):
Played in the world map. I like this one a lot. It just feels right.
Electroney:
Played in almost all the temples. Pretty cool, kind of tech-y sounding song. It matches all the lights and gears and higher-tech things found in the temples.
Elysian Fields:
Very peaceful. It's like, "Hey man, all we really need is love!" LOL JK But really, it sounds like something to go along with a realization that would end up making everything better.
Epic Battle:
Played in orc land. Orc Fortress, actually. LOL Maybe one or two other places that I don't remember. Maybe not, though. Anyway... I didn't tire of it as long as I listened to it while in the orc place. And it fit well. I mean, the orcs could have been eating juicy James while we were looking for him!
Flying:
!!!!!
Played during really happy and surprising moments. Like when Jeanne came back. It made me feel really happy and like everything was going to be better (If it suddenly came on during a rather distressed moment. Like when you are about to be eaten by a dragon???)
Garden of Dreams:
Definitely has a fitting name. Played in the Forbidden Zone. I felt it as a almost slightly romantic song. It really did have a dreamy feeling.
God of the Forest:
Played in Chantfleur Woods and many places similar to the Woods. A really cool song. You'd expect elves and any number of other magical creatures to be spotted peeking from behind a tree when you hear this. Or, at least, I did. lol
Infiltration:
Creepy. But I like Chill Purpose's songs. Indi did a good job picking this out for when we had to hunt down the Rogue. It added to the already tense atmosphere of the swamp. THE ROGUE!!! *GASP!* lol
Kyoto Lounge:
HAHAHAHAHA!!!!! I LOL'd when I heard this played in Mystrock once you go into that castle building (ALRIGHT! I am horrible at remembering the names of places!) Waiting room music? Indi, you are really funny!
Love Loud Beam:
I LOVE THIS SONG!!!!!!!!!!! It is so peaceful and pretty and everything else nice! I'm so glad Indi uses it! It makes me think of a new morning when you are just waking up. Especially when it is played while you are at the Bear's house after failed tests. And it is just really peaceful. Perfect for those small towns. Also a rather romatic sounding song ("Love"Loud Beam?) I'm glad Indi uses it a lot.
Magic Harp:
So pretty! I like this one pretty much as much as Love Loud Beam. It is played in those grey mountains that I NEVER ever remember the name of! LOL! I think it would also work for any place with a lovely waterfall. The notes are sort of cascading.
Metalstorm:
Hmm, I HATE metal music, but this one is actually OK. Works for those battles where you really have to fight hard. It kind of grew on me. Not that I would choose to listen to it but it doesn't annoy me now.
Omen:
Interesting song. Played in the Monastery and cult of the Dragon. I don't exactly know how to describe it. But I do like it.
Patience:
!!! This is just so gorgeous!!! It couldn't be named anything else! It is a little like Magic Harp in the way that it reminds me of waterfalls in how it kind of just cascades. It also makes me think of rainbows and sparkles! Hehe~
Peanuts:
Ooh, this one kind of gives me a creepy crawly feeling. I don't like the loud bangs in it. Not one of my favorites. But it really goes nicely in some of the caves.
Pole Position:
Played in part of Shumen, I think. I like this song quite a bit. Also one of those songs I can't really say much about. But it is just LOVELY when Indi puts it in the game...
Right Behind You:
Now THIS got annoying! I don't know how many times I heard the really horrible noise in the beginning. But another song might not have worked as well. It really got that creepy feeling across to me as I was looking for Merline.
Road to Victory:
Eh... I don't like this one much. But I think Indi put it to good use.
Royal March:
Not my favorite for sure. It goes well for the moments it is played in, though. I just don't like marches much. Hehe!
Skyline:
This one is nice. It reminds me a little bit of Back to Space, but I think this one is better.
Snow:
This one is quite sad. It sounds like a struggle, to me. (An emotional one, of course. LOL) It always made me feel more for the person having a sad moment. I think the best use of it was when Jack was telling everyone about his werewolf problem. Though it was put to good use in several other moments.
Stargazing:
MM1 title screen music. Not much to say, except that it is pretty.
Suspect in Motion:
Eep! REALLY a creepy song! TRUST NO ONE! THEY ARE ALL OUT TO KILL YOU! LOL
Tales from Scotland:
Ugh! I'm hitting myself for not remembering when this was played! I only have faint memory of it... sometime really triumphant?
The Travel:
Hmm, I never thought I'd like this song so much, but I do. Played in Marine's home town.
the Worm:
An ugly song... but I like it. I don't know how to describe it. But now it makes me think of bugs! Especially spiders!
Twisted:
Creeeeeeeeeepy! That's all. CREEPY!
Under the Fig Tree:
Ohhh... it is so calm. So peaceful. It is very warm. A truly lovely and wonderful song.
Creep In:
Hehe! The name fits well! I don't remember where Indi used this, though.