This is a budget series that makes an acceptable stab at the genre. But, I get it. If you came looking for a serious addition to the zombie universe, then you'd probably want to pass this one by.
The sets/locations were fine, the zombies were inconsistent, but good enough and the effects mostly worked. But outside of the action, it was too slow-paced, a little clunky in places, and some of the foreign talent obviously struggled on occasion with their parts.
I got the feeling that some actors had been told to play it tongue-in-cheek, whilst others were told to play it straight, which made it a little confusing, performance-wise:
Two of the 'Squad' got it spot on, playing (and enjoying) their roles to the hilt, whilst the others were a little more one-dimensional in their performances.
The two bad guys 'up top' were a strange couple. Whilst both did a decent job with what they were given (whilst also coming across as being 'in on the joke'), their physical separation across more than half the series, created a difficult disconnect that they struggled with once working together. I also felt their back story could have been looked at in more depth, replacing some of the endless trudging through the underground labs.
All in all, it felt like a decent 8-10 episode show stretched to 13, and it suffered for that. It could have been a lot punchier.
There were a few good performances (Brooks, Thompson, Anna Jones, and the suited guys - Sambuco and Livanov). I'd waste the time on a 2nd season, but they'd really need to pick up the pace or shorten the season.