Fun, funny, addicting, you name it.
Dead Rising is based off of many Zombie movies, Mr. Romero's "Dawn of the Dead" is the most obvious one. It is sort of like a playable cheesy B-Movie splatter film. The mini-bosses can cause some laughs , the dialog is cheesy "I've covered wars, ya know!", and the characters are like those bad actors you like. But thats not what the game is about, the game is about having endless hours of fun.
No matter what, there is always something to do/find out in Dead Rising. Be it doing the story, getting achievements (which is great fun, I might add), or hunting bosses. The game having three game modes (72-hour mode, Infinite Mode, Overtime Mode), and having 6 multiple endings, you'll keep coming back trying to complete the game 100%.
In Dead Rising, as you might have heard, just about everything is a weapon. Teddy Bear mask may be used to blind zombies, Teddy Bear's may be used to battle these flesh hungry monsters, and frying pans can be smacked in their face. If you can pick it up, it can be used to combat the living dead.
And this game is Bloody, with a capital B. This is is not for the faint of heart. Blood is everywhere, several bosses die in gruesome deaths that make you wanna look away (but its so interesting you can't), zombies seem to have buckets of blood inside of them, survivors die in gruesome deaths as well.
The Save system is complained a lot, but I have never had any problems with it. You can only save in one slot per profile, so if you saved in a bad spot, you might have to start over. But don't fret, if you quit and save, you keep your levels and skills. So it gets easier to make it back to where you were. You also can only save in certain Areas (Bathrooms and the Safe Room) and Bathroom's are in just about everywhere in the game. So I never found it annoying or challenging. No auto-save or save-anywhere-anytime here.
The game also has a timer, but not an annoying one. You have 72 hours game-time to find out what exactly happened to this town. Every hour is 5 minutes real-time, so the game is 6-7 hours long if you directly do the story. It took me around 20 hours to finish it though, not because it was hard, but because I loved leveling up, starting over with my same skills/levels, and leveling up some more because I just wanted to have fun saving survivors and killing zombies. But the timer is only in 72-Hour Mode and Overtime Mode, in Infinite mode you have an unlimited timer, but its all about survival. One box of health goes down every 1 minutes, survivors/NPC's are against you so if you kill them you can take their weapons and food, bosses are scattered in new areas, and its the only way to get 5-day and 7-day Survivor achievements.
Like all games though, it has its flaws. The small text for SDTV's is a huge annoyance, and with Capcom saying "deal with it" it isn't very comforting. The character Otis always calls you right when you're in a boss fight, or in the middle of a huge pack of zombies so he can get you frustrated, but I guess in the Zombie movies, there was always one guy you hated. And the official ending isn't a huge disappointment, but its not going to win any awards. The Survivor A.I is awful, horrible even. Makes you wanna kill them yourself, but thats fine, sometimes it fun to throw a person into a pack of zombies, eh?
Overall, Dead Rising is a must buy for your 360 if you like these kind of games. As I said theres so much to do, it'll be worth your money.