By all means, I should absolutely hate this movie. It has low production values, weak writing and questionable acting in it, yet I just can't call this movie a terrible one as well!
No, this of course isn't a great movie but then again, what did you expect from a movie titled "Cowboys vs. Zombies"? Of course it's nothing but a silly and cheap B-movie that indeed focuses on cowboys and zombies. Other than that, this movie also truly doesn't have an awful lot to offer. There is some story but quite frankly I couldn't care less about it and the same can be said for all of the characters. But maybe it actually is a good thing though that the story is never trying too hard to come across as anything clever or too relevant for this movie. It allows the movie to simply be funny and silly to watch instead, which helps to keep it an entertaining enough one.
It's funny how this is a western but the movie absolutely never feels or looks like one as well. Something too modern about the look and feel of it and the movie mostly is set in the dark as well, so most of the time you can't even tell where or when the movie is supposed to be set.
Also really can't say that it feels like a straightforward and conventional zombie movie neither. The zombie elements seem very random really and in a way it even feels somewhat redundant for the movie. It doesn't serve too much of an actual purpose in the story but sure at the same time it's of course also still true that without the zombie elements this would have been an incredible bad and formulaic, low-budget, western. It's basically an excuse for the movie to turn into a "From Dusk Till Dawn" type of movie, without saying that the actual movie is even remotely as good or fun as "From Dusk Till Dawn" though.
It very obviously is an extremely low-budget movie, which becomes apparent through its visual look, acting (though I enjoyed the guy who played the main villain) and sound quality. Also please don't expect tons of gory fun from this movie. There actually seems to be plenty of gore but the movie itself is far too dark for the gore to ever shine through.
Not a good movie by any means but the concept is silly and simple enough for the movie to still work out as some decent enough entertainment.