Just got a game review from playplayfun.com
PLAYPLAYFUN'S IMPRESSION ON RIDDLE CRACK
Riddle Crack is fun to play and it really gets your brain cracking. However, Riddle Crack seems best to be played with friends to have an increase chance of solving the puzzles.
Right about now, the lifeline from the show Who Wants To Be a Millionaire? seems to make sense. I would like to phone a friend Regis!
If you are stuck with a question, there is only a handful of extra hints available at the developer's homepage. Beyond that, all you can do is to ask more friends or to be creative to find your answer through the search engine.
One cool feature from this game is that you can submit your riddle to the developer and if it's posted, you'll get credited for your riddle.