Other than it being insanely hard and super buggy, it was a pretty good game with a pretty good atmosphere. Not as creepy as Lovecraft's novels (despite the title inferring it's based off of Call of Cthulhu, it's actually a mash-up of The Shadow Over Innsmouth and The Shadow Out of Time).
The most frustrating bug in the game, though, is in this part near the end of the game when you're heading towards Devil's Reef where you're supposed to shoot 3 guys through a scope, but they don't appear. According to wikipedia:
The game contains a number of bugs, which have never been officially patched. For example, during one mission the player needs to fire a cannon at enemy wizards. On some Windows systems the enemies are not rendered by the game at all, making it very difficult for the player to hit them. There is an unofficial patch available that fixes some bugs and lowers the game's overall difficulty level. The bugs are generally intermittent, and restoring from an earlier saved game can be enough to get past them.
The wiki article:
Call of Cthulhu: Dark Corners of the Earth - Wikipedia, the free encyclopedia