- Review as requested -
My opinion in general? Honestly, this whole thing could use a lot of work.
Firstly, the VO doesn't change much in tone or delivery. Out of five minutes of dialogue, only about ninety seconds of it display any real degree of emotion or strain. The rest is simply the same tone with occasional accent changes. The writing for the "commercial" bits is distractingly non-commercial. Also, there is something weirdly off about his word stresses. I don't know the reason for this, but sounding like English is your second language will make a difference in radio ads. ...and when radio ads make up 75% of your demo, that's not good.
If you're going to use a "radio-style" delivery, you should use more than just the advertisements. Those only show an ability to read words on a script. To better show tone, try some "station identification" bits - those sometimes wacky, sometimes serious, always corny, and always identifiable sections.
You need to show range more than anything. Considering that this is on Newgrounds, it's probably safe to assume that this isn't for commercial use. It's for saying, "Hey, guys! I'm available for voicing your cool movie!". Cool movies require range, inflection, and characterization, not simply the reading of lines.
That said, try putting together a "character demo" rather than a general demo reel.
I don't consider myself a VO and my opinions or advice on the subject will never be as good as those of actual VOs. That said, take any advice from me on this subject with a grain of salt. There's a decent chance that I don't actually know what the hell I'm talking about.