I tried to avoid spoilers as much as possible on this review, but I might drop them once in a while, please enjoy.
Kill Me Baby is not the show that would instantly grab your average anime fan's attention instananeously. It's a obscure CGDCT adapatation initally panned by anime critics (read: less than a 7 in MAL) with a chibi artstyle and animation so cheap you can't help but wonder if it was done like that on purpose. Despite all that stuff however, lies a great show.

Story
There isn't that much of a story to speak of. The summaries say it's about a highschooler called Yasuna and a contract killer called Sonya. After reading this you might be thinking it's a dark drama, right? Well, it's actually a comedy.
The comedy in this show is a mix between Manzai comedy and slapstick in some sort of way. It may sound repetitive (and sometimes it is!), but the author, Kaduho, makes sure it feels fresh as often as possible.
~~That is, some of the content in the manga was toned down for the anime. I say this as an actual manga reader, by the way.~~

Art
As you have seen from the posters and pictures on the internet. Kill Me Baby is drawn in a chibi (or more properly, Super Deformed) artstyle. Despite what you might believe, this is NOT Kaduho's default artstyle. Just check out his other manga, Kagaku Chop. The visuals are simplistic, with bright colors and don't make the artstyle stick out like a sore thumb.

The animation, done by J.C Staff, looks really cheap, almost like if it was done like that on purpose. If the rumor about the show having the budget of a Video Brinquedo production is true, I could go to Japan in a first-class flight for 3 weeks while staying in a 5-star hotel and eat only at luxury restaurants on a $10 million budget, yet after all of that I would still have enough money to fund 3 more seasons of KMB! Yes, seriously. But anyways, that is what will happen if you have to do 4 shows in the same season, with 2 of them being sequels.

Music
The voicework is really good. If not for Akasaki and Tamura as Yasuna and Sonya, the main characters; the comedy would fall flat most of the time. The character voices in general work really well and if not for things as great as that I would believe the shitty animation was thanks to a messed up production.
In addition, Ai Takabe's voice is refreshingly unique in a world where seiyuus always try to mimic how the most popular ones at the moment sound like. Too bad she got blacklisted from the industry back in 2015 though.

The OST wasn't the best thing ever, but it wasn't particularly forgettable either. As many people said before, the OP is quite annoying, but it somehow manages to grow on you in a weird way.
And now onto the ending, which is easily the most recognizable part of this show. It's great, and people who hated the show otherwise have said good things about it.

Characters
The characters are all based on your traditonal archetypes: Yasuna is the genki who just happens to be the main character, Sonya a "tsundere", Agiri the ~~drug addict~~ Cloudcuckoolander, and the Unused Character is utterly ineffectual.
What ties them together, however; is their own stupidity. They are all idiots on their own way - Yasuna often teases Sonya about normal life, Sonya is absurdly paranoic about everything, Agiri is ~~high all the time~~ may or may not be an actual ninja and Botsu is useless to the degree of having little, if any, lucky moments. There are also one-off "villains", assassins from other organizations.
Flaws
The series biggest flaw is the comedy itself. With it's extremely fast pace, it has to try to throw as much jokes as possible. Hence why some moments can fall flat. Another problem is it's runtime, being a full-length show and hence why people considered it repetitive. If it was a TV short instead most of the backlash could be avoided.

I have to give thanks to Kaduho, Yoshiki Yamakawa and J.C Staff for doing a work like this come to life. And even if you didn't like the anime, the manga is still a work of art.
Thanks for hearing my opinion about this show, goodbye.