Whats wrong with the 11th guest can be very simple put. When compared to its predecessor 'the 7th guest' you can easily make the comparison of comparing 'godfather part 2' to the 'godfather part 3' In short, they tried very hard to make the sequel better than the original in every way, they unfortunately didn't success in any area. That sounds harsh, but totally true, it is inferior to its predecessor in EVERY way. Is it worth playing? play the 1st (massively superior) game and if you really enjoyed it, then go for it. If you don't like the first or found it a bit of a let down, don't even bother with this one because it only gets worse.
This game can (with a respectful nod to Myst) claim to be the title that turned the PC into a serious gaming market. People at the time spent £400.00 on CD-ROM drives to play this £30 game. Why do I mention this? it highlights what a truly awesome and revolutionary game this was. Just look into the history to see how this game invented new and unique technology (cd-rom streaming and FMV compression most notably) and opened up massive new possibilities. I've played it on and off for nearly 20 years and it still manages, every now and then, to scare the poop out of me. As long as you remember that this game is 20 years old, then even if you've never played it I promise you'll love it. The only SLIGHT downside this game has is a rather erratic plot, continuity is a notable issue and there are several holes which the user must make their own conclusions. To conclude, this game rates in my top 5 games of ALL time over all genres and consoles. A must buy!