First, you have to consider that both games are horror based games so they are pretty cool to start with, but extra cool at halloween. Second, Carnevil is a real optical gun game where Zombie Raid is an analog stick game with a shotgun on top. Then you have to consider your playing style. Do you plop quarters in all your games with continue options until you beat them or do you savor the game stopping midways through it so you can try again later to see if you can do more levels on just one quarter. If its the earlier, you can equate Carnevil to 30-45 minutes tops, and Zombie Raid to about an hour or less. If your the earlier type, I would say 1.5 months for Carnevil vrs 2-3 months for ZR. And then there is the personal preferences. Carnevil is the newer and better earner if you were looking at putting it on location, but Zombie RAID is older and would make less. But ZR one of my favorite gun games of all time(right up there with Space Gun and T2). And both have kick ass cabs. So I say get the Zombie Raid, as its my fav. And if you get tired of it, you could always drop it off at my house. But if you like the new games like Area 51, Area 51 site 4, Maximum Force, and Target Terror, you could always convert the Carnevil to those games as well since they have a similar cab and hook up. I think you can convert the ZR to games like T2, Operation Wolf, and a couple of similar ones. Hope that answers your question.