It's important to remember that this is a comic miniseries and not a short-story. The plot has its loopholes and incongruities, but comicbook plots often do. The running joke about tree lobsters is forced. Getting the Creeper to play along does not make the joke work. Characterization isn't at par with the rest of the miniseries either. The cast could've been more synergistic. But all that is secondary.
What absolutely ruins these three issues is Karl Mostert's art. Mostert doesn't know what a human being looks like. Or an animal. Or a crowd. Or a broken wall. His...skies are good, I guess?
Given how crowded Unkillables is, I want to use Issue #8 of Dceased: Hope at the World's end to demonstrate how Mostert ruins everything he has touched in this miniseries. The issue I just mentioned has 4 characters. Just 4. Not a crowd. Easier to do, yes? Well, no.
There's Bobo the detective chimp, who is a toothless crackhead, singing an aria in page 6, panel 1. A drunken dwarf with a broken forearm and a plastic wig on the last page.
Ace the Batdog, who is a weasel, a fox, a hyena, a giant rat, a mongoose in different panels respectively. Too many to reference here.
Krypto the Superdog, who is a rabid chihuahua with botoxed upper lip and a double chin on the cover page. Has a fake left ear made of wood on the last page, and grow and then discards a middle parted hairdo for one panel in between.
The horse does nothing.
And Amy, the...human girl? She had a lumpy face, and then she doesn't. She always has a brow so protruding that her eyes never leave its shadow. Her cranium changes shapes every time she looks sideways or at an angle. From the distance her face looks like a Junji Ito drawing of some eldrich horror. Her eyes exist on a different plane of existence. Her nostrils are swallowed by her upper lip, like some deep sea fish. In the last panel she has clearly transformed into some hellspawn wearing human skin, by the way she can only clench her teeth and grin in anticipation as she dreams of devouring both Krypto and her own nose in one fell gulp.
And there are some zombies. Some of them are from a webcomic somewhere. Some are movie extras, just getting off duty. Some are clearly in a different comics comics wondering why they're covered in blood. Some are mobs from Streets of Rage 2.

Now multiply all of this to fit 3 episodes of Unkillables and with a large roster of characters. Still wondering why I hate Karl Mostert's works?