I love the concept but they need to be fair to the player. There has to be some sort of clue system or solution given at some point to make it actually solvable without hours of random banging your head agsinst the wall. Games that give you any sort of "puzzle" that just requires random BS to solve, quite frankly, suck and it's the sort of thing that makes me stop playing altogether. That was pretty much the reason I quit playing point and click style adventure titles.