Here I Am Again
You were improving so rapidly over the first three installments, but it seems that you've plateaued off here.
Anyway, what's good about this before is still good now: I'm still overjoyed to see the WarioWare characters in a video series, the voices still suit the characters, even if they don't match the in-game voices (though it's hard to figure out what the in-game voices actually sound like, thanks to their echo), and the same nutty style you used before is back, though I prefer the more refined look used in Episode 3.
However, something went wrong in the writing. This seems to be the first attempt to make a premise that isn't already a television cliché (I'm aware you parodied them all), and it ended up being a relatively uneventful episode: Very little happens, and the Kabuki monster seems to be extremely forced. As a result, the episode's climax was undeniably weak, leading to, well, a weak denouement.
My advice: You should play off of each character, like what was done during the Golden Age of the Simpsons. Season 8 alone paired up Lisa with Nelson and later Mr. Burns; Bart with Krabappel and Skinner; Flanders with people outside the Simpsons family; and Marge with Lovejoy. The WarioWare characters have the potential to become equally three-dimensional characters with complex and distinct personalities, there are ample amounts of locales in Diamond City to look for, and there's a fairly large amount of so-far-unused supporting characters (such as Pyoro, Sal Out, and Vanessa). I'd hate to see all this potential go to waste.
As a final comment, I see that the humor is still oriented towards Williams Street. (You know, Aqua Teen Hunger Force, Squidbillies, all that jazz). I'm aware that this is what most NewGrounders look for; the "3" in Humor should be evidence that I don't find the random irreverent humor that funny. I like insightful stuff, like The Boondocks.
By the way, I recently found out that my university (no, I'm not a real doctor; this is merely a pseudonym under one of my comics' characters), doesn't have much in the way of animation classes, so my chances of getting Flash are slim to none once again, and now I have a half-finished script. Thus, I'll be happy to help with the writing, and if all goes well, I'll be getting sound and editing equipment as well. Of course, like I mentioned, my approach to writing is much different (character-driven, plot-heavy, and often chock full of social commentary, but that's the kind of comedy I dig).