That's retarded. Voice acting is tough to begin with, and "good" voice acting can still be pretty subjective. The fact that the game had enough development and dedicated crew to make a story and voices in the first place is pretty cool; it's not the original guy's fault.
I don't think I've even encountered those characters yet, and I'll admit I'm honestly just biased against story and dialogue in most games on principle. In certain circumstances, it works, but more often the voice actors are freelance/amateur, the scripts are awkward, or the voice director doesn't quite know the proper emphasis and inflection to add to the performance. Freedom Planet also suffered from uneven volume levels between characters, which probably should have been fixed in editing...
Once I've beaten the game in classic mode, I'll go back and do story mode. I mean, I sat through all the bullshit stories of the actual Sonic franchise (water monster, hedgehog clones, sentient robots, aliens, bestiality, werewolf transformations...), this has to be at least better than those in some sense :P Congrats and thanks for whatever part you played :)
tbh, my biggest complaint is the menu glitch in the target time trial mode... sometimes you can attempt restart a challenge too fast, and the menu bugs out and shit. Annoying lol