Good stuff!
Fantastic work here. Its not in the range of voice, but more in the miner nuances that give the characters CHARACTER. It doesn't feel forced or faked, and was quite funny at some parts.
You do need a new mic BADLY though. Its a shame to let a $10 peice of equitment hold back talent. The current mic you are using s dull and muddy, and stands out even more when mixed with crisp clear sound FX.