It doesn't seem similar to me at all, except for the setting being a mall. I've seen Dawn of the Dead. Other than being in a mall and having everything in the mall at your disposal, it doesn't seem connected at all.

I always pass the game at least once, depending on the game. Then I'll use a guide or maps for things like the pigeons in GTA IV. Even if I've passed it, I have to really like the game to try to get all the achievements and things. Saints Row is an example. I don't have a guide for it, but you can find the maps of the tag and CD locations. I haven't done it and don't plan on doing it because I have much better games in my opinion, and I don't plan on getting all the achievements for Saints Row anyways. The other achievements (like the multiplayer achievements) are very time-consuming, and I'm not worried about getting Saints Row 2. For GTA IV I used my strategy guide to get the pigeons and to find the characters you meet FASTER than I would just wandering around. I don't sit down with a new game and a strategy guide.

For 95% of things, I won't use a strategy guide.