Nothing you haven't heard already
You definitely should have finished it, but that you knew. Anyway, I wonder if I could ask... what WOULD have happened if you had gone all out and finished it the way you had wanted/intended?
It is a shame that it ended like this since you'd put so much effort in the previous episodes, but I guess sometimes you just have to finish what you started even if it means cutting corners.
In terms of visuals, the animation was brilliant as usual. (Though there was one error I saw... when the nukes were about to hit, the truck the characters were escaping in appeared to be driving backwards. XD)
The audio was fine too, but I guess one of the unfinished parts was the voicing for some of the characters?
Plot--- Yes it wasn't finished, but the story doesn't necessarily end with the nuking of the city since in the previous episode, wasn't the girl bitten? So there is room for continuing if you ever chose to pick it up again.
Still, who knows maybe someday it could be finished, if not... that doesn't matter, just as long as you keep making cool animations like this series. You've got some serious talent!