Nicktoons Unite! (Nintendo DS)
SEQ_TITLESCREEN.sseq with the standard soundfont
Inside the "/data/audio/sound_archive_mus.sdat" archive in the ROM, there is a file reffered to as SEQ_TITLESCREEN.sseq, this file is not used for the game's titlescreen and is incompatible with the game's soundfont.
SEQ_TITLESCREEN.sseq with a MIDI compliant soundfont
If matched up with a MIDI compliant soundfont we can hear that this track is "Cross of the Blue Moon" from the "Castlevania: Dawn of Sorrow" intro cutscene. This is most likely not a direct rip of the song, as it has differences in timing. (The following upload also has adjusted timing for some instruments)
AMBIENT_GENERIC_TEST.SSAR and HUB_TEST.SSAR
Inside "/data/audio/sound_archive_ambient.sdat" archive in the ROM in the SEQARC_AMBIENT_GENERIC.SSAR and SEQARC_HUB.SSAR files there is a test sequence under the name "AMBIENT_GENERIC_TEST" and "HUB_TEST".
Found in "/data/ui" is a file named splendid.tit. It's unknown what this does, but loading into Notepad++ it shows the names of some .pal files, possibly for color palettes on stages and screen, but I'm not sure about this.