First of all...
My review may look a little bit 'biased', this is because it's what I think this game deserves.

Yes, even if it's merely an 'expansion', what the author did was just stupid.

If you want a bigger review, please check my review for "Protector IV".

Let's begin the review itself.
Protector IV.V is pretty much an 'expansion' to Protector IV, similar to Warcraft III's Expansion, "Frozen Throne".
And I say "similar" to that because it is very similar; you don't get one game with an expansion pack, you get a game with an 'expansion pack' that acts like a different game.
That is bullshit.

But it gets worse, I say similar but not identical, because IV.V adds content TO IV itself.
If you compared it to Warcraft III's Expansion Pack, what it does is add content to Warcraft III as well as give out more content. That is different.

And what does it add to the game?
From what I noticed, there's actually a way lot more quests than in IV, of different factions.
There's also a few more heroes, but they're probably all from Protector IV, the variety is dumbly under-worked.

And that's pretty much it.
The only confirmation is new quests, plenty of new quests, but nothing else is new.
The quests don't even add anything to the story if there's even a story, it just makes new stories that stereotype the stupid meaningless factions Protector IV has.
Sure, the quests are actually fun, in some way, for some. But other than that, Protector IV.V is literally an expansion to add to Protector IV.

Then why is it a different game by itself?!
By doing this, the author pretty much changed how Protector IV itself should be played.
There's a separation of two games, and the one you should (or even must) play is Protector IV.V.
Protector V shouldn't even exist when this one does.

The biggest problem may be the fact that, if you want to play the game AND get the badges in Kongregate (Sounds a bit insane to me, actually), you'll have to play Protector IV and Protector IV.V. Or you know what? Fuck it, go get a .sol for both or cheat it out hastily.
I find it rather ironic how both have badges though, yet there's only one for Protector IV.V, probably because the badgemakers expect it to be annoying to get it all.

And just in case you wonder if the saves are shared from IV to IV.V, they are not.
An already bad move for an even worse move.

So yeah, Protector IV.V is essentially Protector IV with new quests, nothing else is new. For that reason, I lower the "game" (it's not even a game, let alone a proper expansion) value.
Would have been better if the author simply updated Protector IV so it had the quests from it and all, but no, he just decided to 'make another'.
If you want to play Protector IV without worry about badges or whatever, just play Protector IV.V instead then.