Super Mario Bros. X Forums

-Intro, hub and ending-
1) Mist Continent: Noe Town (Pokémon Super Mystery Dungeon)
2) Patched Plains - World Map (Kirby: Planet Robobot)
3) Resolution Road - World Map (Kirby: Planet Robobot)
4) Gigabyte Grounds - World Map (Kirby: Planet Robobot)
5) Rhythm Route - World Map (Kirby: Planet Robobot)
6) Access Ark - World Map (Kirby: Planet Robobot)
7) Cheerful Interlude (Mario & Luigi: Paper Jam)
8) Dark Clouds (Kirby: Triple Deluxe)
9) Boss Intro (Donkey Kong 64)
10) Item Room (Super Metroid, loop by h2643)

-Jaj Van Plains-
1) Green Gears (Kirby: Planet Robobot)
2) Patched Pathway (Kirby: Planet Robobot)
3) Pac Village (Pac Man World 2)

-PGE Tubular Forest-
1) Another Medium (Undertale)
2) Flarefrost Galaxy (Super Mario Galaxy 2.5)
3) Somnom Woods Remix (Mario & Luigi: Dream Team, remixed by Enjl)

-Electric Airship-
1) Cloudtop Cruise - Thundercloud Version (Mario Kart 8)
2) Techno Tower (Kirby: Planet Robobot)
3) SMB Airship - Edit Mode (Super Mario Maker)
(4) Challenge Accepted (Shantae and the Pirate's Curse))

-Technological Drainpipes-
1) Haltmann HQ (Kirby: Planet Robobot)
2) Laser Area (Kirby: Planet Robobot)

-Overload Mechanism-
1) Munitions (Spiral Knights)

-You're a dangerous nun, yes six six six-
1) Boss Intro (Donkey Kong 64)
2) Darkness Returns (Kirby: Planet Robobot)
3) Sullied Grace (Kirby: Planet Robobot)
4) D3 Theme (Kirby: Planet Robobot)
5) Company (Kirby: Planet Robobot)
6) The True Arena - Battle Theme (Kirby: Planet Robobot)

-Final Boss-
1) P-R-O-G-R-A-M (Kirby: Planet Robobot)

-Sea City-
1) Sea City (Kirby: Planet Robobot)

-Mountainside Peril-
1) SMW Athletic Theme - Hurry Up!! (Super Mario World)

-DontYouForgetAboutMe-
1) Citadark Isle (Pokémon XD: Gale of Darkness)
2) Cipher Admins Theme (Pokémon XD: Gale of Darkness)
3) Alraune Whisperer of Dementia (Bayonetta 2)
4) Prediction! "Defy The Legends" (Pokémon Super Mystery Dungeon, by PMD4)

(-Hell-
1) Sonic the Hedgehog 3 - Lava Reef Zone)

Yes, again there's a lot of Kirby music in this game. You can also find some unused songs that for some reason weren't deleted from the game files >_>