Hammer and Bolter does a great job in rendering the grim, hopeless universe of Warhammer 40,000, but can't hide some of its biggest flaws.
The episodes range from self-contained adventures of unnamed characters to events that intersect major plot points and figures already established in the books, and I think Farside Features completely nails the atmosphere in each episode, mixing the over-the-top essence of each situation with a subtle hint of dark humour.
When it comes to visual quality, Hammer and Bolter mixes static background paintings with moving characters, much akin to the "saturday morning cartoons" many of us grew up watching - a choice that not everyone will like, but isn't a flaw per se.
However, it is easy to see how some episodes rely too much on the story and too little on the actual animation, resulting in something that looks more like TV comics than actual "cartoons", and might be underwhelming for some viewers.
However, every episode, even the most flawed, has some redeeming quality. I would say Hammer and Bolter is worth a watch.