Actually, I haven't been playing with a guide either. Not really. There are a few specific things that I wanted to know about, and that's when I ran across the Zombie Genocider achievement. As I said, I didn't cheat in learning how to do it. It became fairly obvious when I realized the carnage vehicles do, and that those vehicles respawn when you go between areas that have to be loaded from the disc.
There's no boss involved in getting complete access to the tunnels.
The key is hidden in a store room, somewhere in the middle of the map. Otis will even tell you (if you bother with the damn phone, which thankfully works as you drive) when you first enter the tunnels that he left the key in there somewhere. It's good to get it at the beginning of a game, when you have plenty of time to run around.
Yes, definitely, I feel the game was a great purchase now. For a while there, I felt cheated. Glad I was stubborn enough to stick with it. Had I acquired this game in some other way, as I have some PC games (er, eval versions, yeah . . .) then I doubt I would have had the motivation to stick it out.
Edit: On a wildly different subject,
the vs CPU and puzzle/mission packs for Lumines Live will debut at 100 pts each for about a month, starting on the 24th. (Regular price after: 300 pts each.) Q? and M$ have gotten hammered for the distribution model used by this game, and to some extent, I agree with the criticism. It's a lousy precedent. The total cost for base and advanced single-player I think is around 1800 pts, or about $22. Add more packs at the expected 400-pt-apiece price, and you end up paying more for the game than you should. At 200 more points total, though, the whole thing ends up costing $25, which is not bad for what you get. This is not an ancient arcade game, or even a rehash of an ancient arcade game. It's something pretty special, I think, and $20-25 is not a bad deal. Plus you really don't need to buy the whole shibang, if all you ever play is challenge mode.
There will be an extra skin for Gold members, free. I'll make sure to grab it before my gold expires early next month.