A very good idea brought down by one design flaw after the other
On the plus side: yes this game is funny. Some of the weapons are absolutely hilarious, and the plot and characters are a delightful over-the-top camp fest. But there isn't that much plot and and the novelty of the weapons quickly wears off.
What you are left with is an extremely basic third persion action game..the combat system is simplistic (left click to hit something), the controls aren't terribly responsive, and the hit detection is pretty far off at times. There is very little challenge in 90% of the combat; what challenge there is comes from apparently random grabs by zombies and the fact that you get bitten to death because the game doesn't pause while you access some menus or change outfits..which is just plain cheap.
What's even cheaper is that the game combines the lamest save system in recent memory (no autosave, you can only save at very select locations) with a tendency to throw absolutely impossible stuff at you without warning..which then causes you to either rage quit, replay half an hour of boring content, or restart the entire game all over. This is not challenge. This is cheese.
And I can go on an on, there is an entire bus load of horrible design decision or stuff that just doesn't work; followers that move slower than a snail; friendly fire between you and your followers; followers just not coming with you; horrible inventory management. items that break way too fast.
I guess there is something to be said for Dead Rising 2 as just a zombie killing sandbox, and it can be moderately fun as such. But the game goes to such great lengths to make your life miserable that any lasting appeal is rapidly ruined.