In each round, you are given a pool of 16 letters and a word to find using said letters. Letters may appear more than once in a hidden word. To solve each puzzle, type or click the letters to make a word (working around the brown given letters, where provided). Letters that are correct and in the right position in the word are marked in green, and letters that appear in the hidden word but in the wrong position are marked with yellow. Letters that aren't in the target word remain gray and are shaded in your letter pool. Using your powers of deduction and your massive dictionary brain, find each word before time runs out to move on to the next round.
Each level has three words, and beating two levels unlocks a bonus round where you can rack up points by finding as many words as you can that start with a given letter (or, you might get a "sunob" round where you have to input all of your answers backwards, but for double the points). The letters given to you at the beginning of each puzzle will jump from position to position and eventually disappear completely before the words grow in length to five, six, or more letters.
Analysis: If the format of Wordspector seems a bit familiar to you, it's comparable to a word version of Mastermind, or perhaps a bit closer to the game show Lingo. The major difference is that instead of a limited number of guesses, you're racing aganist a clock. Thus, it might be to your advantage to make many guesses to narrow down the possible letters if you're stuck, however this also diminishes a bonus available for guessing correctly in fewer words.
One tricky factor to work around when playing this game is that levels often come with a given letter (in brown) which must be used in any guesses you make. Unlike Lingo, you're not allowed to make any guesses that deviate from the given letter, so if you've got an odd letter in an unnatural spot, you might have a harder time coming up with any guesses at all. In one instance, I struggled to come up with a five-letter word that ended with an X. Similarly, while having only 16 letters to choose from narrows out some possibilities, it also means that there are 10 letters that are absolutely not allowed in your guesses, limiting you further. The only word I could think of that fit the above condition was "affix", but not having an F in my pool prevented me from guessing that. There's a hint button for an extra free letter nearby, but you may eventually find yourself using it often because of these limitations. (The word turned out to be "index", by the way.)
With most word games, there seems to be one issue or another with the dictionaries used to compile the word lists. Normally the complaints seem to be that the word lists are too small, but in this case, it almost seems as if the word list might be a bit too large. We've not yet submitted any words that the game didn't find valid, but the game has selected some obscure words for us to guess (this is where the deduction element really comes into play).
That much said and done, there's nothing wrong with challenging your brain a bit, is there? Whether it's feature or flaw, Wordspector takes a familiar challenge and puts a new twist on it that will have you fingerprinting the dictionary for clues.