Arachnid is well written, the plot not too complex but complex enough to keep you interested. The violence isn't overly graphic but rather falls somewhere in the middle despite the amount of gore involved. There are times when the girls are over exposed but this is limited. One of the girls, a minor character so far, has ridiculously large breasts but that's just to be expected, no? There's a lot of challenging and grand standing too. There's also, finally, a gay man featured but without delving into romance - his plot is vengeance for his unrequited love's death. Matched with him is a slavering lesbian interested in following Alice. You'll understand what I mean by slavering if you read it as she is also one of the insect assassins. Also, several of the girls go through phases of hating and then liking each other, forming a sort of friendship that vaguely functions. Does this sound all rather normal for a manga?
Well, here's where it gets a bit loopy. Each of the main players in this manga has an ability that resembles those found in various insects and arachnids. A great deal of detail is put into explaining insect behaviour and characteristics as well as how the main players' abilities resemble those of their namesakes. There's a cockroach girl, a cricket boy, a spider girl (Alice), a bee girl, etc. And they all happen to be assassins working as a group. All except Alice, that is. Alice becomes the outsider the assassins just can't leave alone and so round battles ensue.
Mash this all together and I was left wondering "what is going on here?" at the same time as I got thoroughly addicted. I'm not sure if the addiction comes from needing to know the answer, the amount of interesting details in the manga or the complex action that definitely appeals to the young at heart (I'm one to giggle uncontrollably at slapstick...).
And, if you can't get enough of the insect assassin madness there are Caterpillar (an assassin insect people spin off) and Jackals (a story on a group of assassins) for you to discover.
The art of Arachnid was created by Ifuji Shinsen and it is quite well done. The style isn't overly new or old or unique with regards to manga trends but it is lovely to look at. It is dark at times and full of shades of grey (dammit, that phrase has been destroyed!). What does stand out is the level of movement within the art. Sometimes capturing a moment as art creates stillness when portraying movement was the intent simply. Not so here. Wherever possible Ifuji Shinsen has illustrated action and this pulls you along. Where the plot sometimes stalls as the writer provides great amounts of detail on the insects (known to writers and publishers as info dumping) Ifuji Shinsen illustrates in a manner almost like those found in biology texts but with an emphasis on action where possible. Otherwise, when action is impossible, the emotions are highlighted to create depth. All in all, between the art and the writing there is a kind of skipping pace to Arachnid, one not normally found in stories nowadays and this just provides yet another oddity to be intrigued by.
The quality of manga readers can vary. The uploads are often done cheaply or as a serious hobby by a collective. Be aware that sometimes licence hasn't been given but the sites noted above, Manga Fox in particular, are extremely careful about adding and pulling mangas according to license agreements. So you shouldn't have to worry too much about the material being pirated. There are also translated works and non-translated. Amongst the translated works you will find that the quality of translation may vary according to the skills of the translators. Usually the works are perfectly readable anyway, with only a few added or dropped words or a word in the incorrect tense or with/out plurals. But sometimes the text becomes gobbledygook. In which case, either seek another version or give up and buy an official copy once a printed translation comes out. The other issue of note is you may need to expand the screen to read the text easily as sometimes the scans are minimised a little.
I find that if a page doesn't download properly or some other issue occurs (too slow or someone ordered the pages incorrectly etc.) with one reader then skipping across to another reader and picking up where I was is quite easy and rarely annoying.
Otherwise, enjoy and watch out you don't get too addicted you forget about the necessary things in life.