It is pitch black. You are likely to be eaten...

Hitchhiker's Guide was the most obnoxious of all of them in the "early decisions can doom your game in non-obvious ways".

Those who know about the cheese sandwich know what I'm talking about. Those who don't are either still mad, or blissfully unaware.

Maniac Mansion was brutal for that too.

I loved that LOOM didn't let you progress unless you had done everything that would allow later-game moments to happen

Zork Anthology is $6 on gog. Includes Zork 1-5 and planetfall.
Runs on XP/Vista/7
www.gog.com/en/gamecard/the_zork_anthology

I love the action castle things too.

Black Barney wrote:

Maniac Mansion was brutal for that too.

I loved that LOOM didn't let you progress unless you had done everything that would allow later-game moments to happen

Hitchhiker's Guide seemed to actively encourage you to move on, thinking you were making progress, when you really were just digging yourself in deeper into a now-impossible game. Maddening.

The old Sierra games had that problem (King's Quest, etc). If you missed something early, you didn't realize it until way way later. Not fun.

Zork 1 online HERE , and

Hitch-hikers HERE

I was in my drunken early work years when these game out so never really got too hooked - me and my mates spent our money on beer and parties and trying to chase women and car trips to drink beer rather than computers.