honestly (coming from someone who's literally made two of this exact same kind of mod) this is very much the epitome of "i'm going to edit the existing movesets to make them 'better'" mods, fit with the obligatory spindash changes, jumpthok and hueshifted skincolours.
to be fair though, it's not entirely horrible. there's very little to be analysed, sure, but most of what's here is decent. sonic and knuckles are both competent, even if they're very much unbalanced. knuckles loses barely any height and moves much faster, but the addition of multiability makes the moveset flow much better.
tails is where the mod falls short, though. combined with the odd visual bug of him squishing when he runs out of flight and in general being much faster than necessary, his flight being extremely strong and unbalanced makes for an oddly boring play experience.
overall? not horrible, but definitely the kind of mod you'd think of when "moveset altering modification" is brought up.