This is a B-Movie, to be sure, with the requisite bad acting and feeble effects, featuring "fast zombies", kind of a cross between traditional zombies & 28 Days Later.
The trouble was in their inability to keep their zombie lore straight for 10 minutes without changing it around. They were all over the map trying to hit every trope existent without any rhyme or reason to tie them together cohesively.
At a running time of 1:55 this was at least 30 minutes too long. Making it shorter could have avoided some of the more painfully indulgent scenes near the end.