I mean it is in third person, where you and a buddy can shoot the hell out of zombies. (Who wouldn't like that?) The fact is, you'll enjoy Resident Evil 5 more then Halo. (Unless your a Halo diehard)
You can upgrade weapons and aquire new ones. Plus it's tons of fun with a firend.
Halo on the other hand, is a RTS game, so I'm not sure how much you like those types of games. Also, unless your really into Halo, and know what's going on, it won't make sense to you. (Where's the guy in te green armor!?)
Although they are different games,they can still be compared,although its not really which is better,its what kind of game you prefer,RTS or TPS.Personally,I've never been a big zombie killing fan,or a Resident Evil fan,but I never played Halo before Halo 3 about a year ago but I think Halo Wars is better.