Gradius - Beginning of the History: Not a bad remix, but track 1 is a bit more sharp than it needs to be. I'd suggest making it have less of a "ringing" sound.
JJBA staff roll: Similar complaint as previous song, but a bit worse in this case. It seems that several tracks are too loud, which makes the song a bit irritating, not soft enough to capture the feeling of the original, and it makes the different instrument tracks not blend together very well.
Salamander Unused 1: I liked the sound of this one, the only problem I had was that, similar to before, track 4 was too loud, which made it sound a bit jarring. Ideally, you want a track to naturally stand out by sounding distinctive with its own melody and having the right instrument choice that makes it really stand out from the other tracks. Making it significantly louder isn't the best approach and comes across as desperate.
Nazo no Kabe block kuzushi Password: The transcription of the notes and the instrument choice was solid. The only problem I had with it was, again, the notes were too loud. It's supposed to have a soft tone like the original, but making all the tracks so loud makes the whole song come off too strong and makes it fail to capture the calm and tranquil feeling of the original.