Hacka Doll The Animation is like Teekyuu but on less drugs. Hyperactive girls doing silly and nonsensical things with no real continuity. Hacka Doll makes the jokes easier to digest, but Teekyuu has more raw insanity, so it's a toss-up whether you'll prefer one over the other.
While most of the studio trigger has been working on many large scale projects there was small team which was focused on these "shorts" (shows with short episodes) which are in many ways better than their large scale projects. These short shows seem like passion projects which frequently reference Trigger's (and Ginax's) past works. Unfortunately these shows are still overshadowed by popularity of Trigger's larger projects.
Similar artstyle....too similar in my opinion...and characteristics of each girl, for example : HackaDoll No.1 = Muromi-san........... HackaDoll No.2 = Levia-san........HackaDoll No.3 = Yeti girl.....
Both shows have awesome OP songs [ damn, I just love them... and you will also ]
Both relies heavily on comedy genre.... fast paced action/gags...which leaves you a feeling that you want more and more.... pretty much there is no storyline, but there is one thing that HackaDoll anime doesn't have like Namiuchigawa no Muuromi-san.... that's male MC.... but I think that he is not needed in HackaDoll because it's enough already of these 3 HackaDoll's....
In shorter... it's basically the same show, so if you like'd one, you WILL like another by 100%.. read more
I find that Hacka Doll is similar to Ai Mai Mii with the insanity of the episodes and the constant wtf, Ai Mai Mii is more slice of life/comedy, and Hacka Doll is more of a sci-fi/comedy, both shows are very all over the place and have very expressive animation styles.
Another comedy about a group of incompetent girls with superpowers supervised by a big breasted adult, and an obvious reference for Hacka Dolls --there are winks to Milky Holmes right in the opening animation. Milky Holmes (seasons 1 and 2 only) is like the crazy uncle to the more subdued Hacka Dolls.