A few days ago, I accepted a side-quest in Megaman Starforce 2 that has lead to me taking a short break from the game. The basic premise of the job was simple enough: the player has to follow a clue and examine the corresponding object, which would give the player a new clue, and so on. However, the moment I read the first clue I was immediately stumped and overwhelmed.
The first clue was two simple words: "Ancient fish". Immediately, several possibilities jumped into my mind, such as the bottom of a lake I visited earlier in the game and the ancient drawings and fossils of sea life in the desert. Unfortunately, getting to those areas could some time, so I was looking forward to spending half an hour running around the game world. Thanks to a suggestion from my brother though, I did find the correct location pretty quickly; it was a fish fossil in the nearby museum. The next clue was where things really got hectic. I was told to look for "four wings that catch the air". Naively thinking the second location was somewhere nearby, I spent a long time checking nearby areas for anything matching that description. Nothing. So I followed my instincts and went to check out the only thing I could think of: a dragonfly fossil tucked away in a remote, hard to reach corner of the desert area. When I finally got there, I discovered that there was no clue, and that the entire trip was one big waste of time. Shortly thereafter, and after having spent an entire hour on this minor sidequest, I gave up in frustration and checked GameFAQs. It turns out I needed to go to the lake town's windmill.
This is a pretty good example of why it can be a very bad idea to put a riddle into a videogame. When some developer came up with the "four wings that catch the air" riddle, he must have thought that the answer was pretty obvious. Unfortunately, game developers can't afford to assume that the players will think the same way that they they do; what may be obvious to one person may be the last possibility on someone else's mind. Compounding the problem in this case, the developers overlooked an obvious alternate solution: the four winged dragonfly. Honestly, I had completely forgotten about the existence of the windmill by the time I accepted the sidequest. I would have figured it out as soon as I saw the windmill again, but the lake town would have been the last place I would look, since it is the hardest area to reach from where I was. After my initial guesses failed, I had only two recourses: go over every area in the game with a fine-toothed comb (which can take hours), or cheat and look up the answer.
Honestly, I think puzzles like this one should never be put into video games. Scavenger hunts with vague clues can be fun only as long as the conditions are reasonable. As long as the area of the scavenger hunt is restricted to a small size, the player has the luxury of getting to know the area in detail and being able to use the brute force approach without wasting an undue amount of time (this was the case in the underwater scavenger hunt earlier in the game). Alternatively, the game can provide the player with additional clues if the player gets stumped earlier on, so the player's brain has more information to chew on. However, demanding that the player go over the entire game world with only a vague clue to go on is simply a bad idea. It only leads to frustration.