This movie wasn't nearly as bad as Zombies 3 was. Overall, I'd say Zombies 4 is an alright movie. Nothing about it was particularly good but none of it was that bad either.
I will say, though, at this point in the series, it feels like the franchise isn't about Zombies anymore, like they had so little to do with the plot. I also get the feeling that none of the Zombies will be in Zombies 5, so yeah.
Also, in the first movie, it was established that Zombies have an irrational fear of fire, so for the Zombies not to react at all to the Daywalker's fire felt a bit off.
I have a few more nitpicks, but I won't list them all here because, at the end of the day, this movie is just ok.