Hataraku Saibou is a very enjoyable and educational show that seems to be a bit polarizing, with some people praising or ridiculing the light-hearted and slice-of-life feeling of this 13-episode run. I will admit that I got tired of the show about halfway through the season, and only picked it up a few weeks later as the lack of a contiguous plotline and limits to character development made it hard to binge with so many other great anime out this year.
As a watcher, I feel that this isn't a show you should binge but rather enjoy periodically.
SPOLIERS:
There isn't really much of a story in this anime, and the major development in the show seems to more about the cells themselves rather than the body they're in. There is a lot of screen time given to the main ship in the show between the red and white blood cell, but it doesn't really develop into anything. And sadly, it can't really since they're cells.
While there was an attempt to significantly expand the depth of the various blood cell characters in the middle of the season, I feel that it didn't really lead to anything. For example, the entire episode devoted to the childhood rivalry between the Killer T cell and Helper T cell didn't really give us anything other than a few chuckles.
But there is definitely some really good content here. Hataraku Saibou isn't that serious of a show, and at times seemed to poke fun at anime itself with the fight scenes. I also found the analogies that the show makes to real biology to be very clever. Platelets being lolis carrying coagulation factor and fibrin sheets, white blood cells being patrol officers, red blood cells carrying oxygen and sandwiches on occasion down "highways"... it was very creative and fun.