Let's try to fill in some of the blanks on these missing artist infos (some of these may be redundant due to later ones actually filling in the blank)...
Originally posted by Desert
I was unable to find a composer for Duck Life 3: Evolution, so that's Wix Games sound team for me. UPDATE: K.T.B on the Discord told me it could have been Peter Carr. I see that as plausible, since he actually did do some music for some Duck Life games (I'd have to do more research, though).
The composer for Stardew Valley is ConcernedApe.
Originally posted by Dark Mario Bros
The composer for the opening theme for Super Smash Bros. Brawl is Nobuo Uematsu.
Originally posted by OEO6
The composers for Mighty Final Fight, citing the end credits and
VGMPF's identifications, are Setsuo Yamamoto and Yuko Takehara.
Originally posted by detdu
For Katana Zero, the YouTube video credits LudoWic as the composer.
For FTL, the composer is Ben Prunty.
For Celeste, the composer is Lena Raine.
Originally posted by Infinity
For Mega Man X4, YouTube video cites Toshihiko Horiyama.
That's two in a row for Lena Raine, since I listed Celeste's above.
For GOTCHA!, Youtube video cites Nik Kershaw.
Originally posted by MrMartley64
Found this official version that tells me the composer is Mike Geno for that FNF song.
Originally posted by Doug Walker
Ah yes,
two mystery songs with no known artist info. I'll just note Fond my mind under "Transamerica FM Brazil" and the most mysterious song under "NDR" (after the stations they were run off of) for sorting purposes.