I'm gonna try to do this but I'm doing it in much harder mode:
- No games from USA
- Has to be released after 2010 (or re-released for day 18)
- No Nintendo games https://twitter.com/kuraine/status/1296473954513752065

Day1 (Title Screen Music): God Hand (Clover Studio) - Be Ready for it! likely composed by Masafumi Takada
Still one of the best beat them up out there https://soundcloud.com/user526376167/god-hand-ost-be-ready-for-it-track-01

Day 2 (Opening Level Music): Sonic Adventure 2 - Escape from The City by Crush40
because I just can't make a playlist without Sonic https://soundcloud.com/sonicunleashed/sonic-adventure-2-escape-from-the-city

Day 3 (8bit Music): VVVVVV - Positive force by Soul Eye
https://souleyedigitalmusic.bandcamp.com/track/positive-force
I just can't get enough of this
hopefully this is 8bit but I'm not sure

Day 4 (Console-Exclusive Title): Bloodborne - Hail the nightmare by Ryan Amon
https://soundcloud.com/lord-fhalkyn/bloodborne-ost-hail-the-nightmare
I just love it so so much

Day 5 (Hub/Over World): Final Fantasy Type-0 - Standing Strong on the Ground by Takeharu Ishimoto https://soundcloud.com/wanderingsouls/standing-strong-on-the-ground

Day 6 (Relaxing music): Heaven's vault - The Age of Sail by Laurence Chapman
https://laurencechapman.bandcamp.com/track/the-age-of-sail
Heaven's vault still on my top 3 of the whole generation

Day 7 (From an indie game): Redout - You Will Burn aka "Volcano" by Aram Shahbazians
https://soundcloud.com/tyler-hughes-65/09-you-will-burn-redout-ost
Still the best futuristic racing game ever made (yes I include wipeout)
Not sure if it's a "30 day music challenge" or "thread about all games I won't stop talking about"

Day7 bonus:
Redout also has the best Drop in the entire galaxy https://soundcloud.com/tyler-hughes-65/18-nearby-stars-redout-ost (synchronised with a massive jump if you play well enough)
and the most epic music of any racing game:
https://soundcloud.com/tyler-hughes-65/14-red-storm-redout-ost1 (0g track in a asteroid field)

Day 8 (From a shooter):
Decima from the PS4 exclusive Launch title that everyone forgot Resogun by Ari Pulkkinen

Day 9 (From a licensed game):
Not sure what it exactly mean so I'm assuming is a game with a licence coming from outside of games
Transformers Devastation-Starscream https://soundcloud.com/user-802688108/starscream-transformers-devastation-soundtrack
A highly underrated game BTW

Day 10 (RPG battle):
Initially I intended to go FFXV but you know what I’m keeping it for another day.
Final Fantasy 7 Remake - Let The Battles Begin! (A Merc's Job ver.) by Nobuo Uematsu https://soundcloud.com/kakyoin-dies-566727774/ff7-remake-ost-let-the-1

Day 11 (puzzle game music):
I had to choose between talos principle, gorogoa and tetris effect but as this is also “a thread about all games I won’t stop talking about” here is GNOG - PURP-L by Marskye instead https://marskye.bandcamp.com/track/purp-l 

Day 12 was supposed to be a music that make me sad.
But you know what Fck sadness and Fck rules.
Here is a theme that make me happy:
Issun's Theme in Okami by Masami Ueda https://soundcloud.com/llamas-wod-junk/okami-issuns-theme

Day 13 (Music I like from a game I don't like):
I think I've shared this theme about 200 already but the game is so bad the soundtrack so great I just don't want it to go unnoticed.
Romulan battle suite on Star trek online by Kevin Manthei https://soundcloud.com/mmomusic/star-trek-online-10-romulan

Day 14 (featuring vocals):
I originally intended to post The Origin from Zone of the enders (by Maki Kirioka) but Wikipedia tells me the game was released on 2001.
So here is RULES OF NATURE Metal Gear Rising by Jamie Christopherson
https://soundcloud.com/jimnoneother/metal-gear-rising-revengeance-music-rules-of-nature-with-lyrics

Day 15 (Boss battle):
You know I have to add Devil May Cry somewhere in this thread
Here is Cerberus Battle in Devil May Cry 3 by the legendary Tetsuya Shibata https://soundcloud.com/drunkenpanda/devil-may-cry-3-cerberus