Cluzzle is a party game. Period. If you try to play it "seriously" or with too few people it likely won't go over too well. Having said that, the game can be quite fun and good for some laughs.
Cluzzle is a game in which each player (up to 6 - but there's no reason why you couldn't add more by adding more colors) is given a blob of play dough and a few "guessing" tokens. Each game is played in 3 rounds in which people try to use deductive reasoning to guess each other's sculptures (based on drawing cards and choosing from a list of objects on those cards.)
Here is what really makes the game clever though: There are no teams, and you DON'T want to make your sculpture too good! You see if your object is guessed immediately and by everyone you will earn a point, but so will everyone else - essentially not progressing you toward victory any further. However, if it is not guessed at all you don't get any points. Since each subsequent round awards more points you want it to finally be guessed after 2 or 3 rounds of answering questions (Yes or No questions such as "Is your object edible?" or "Is it something you can wear?")
So the best you can do is have your object guessed in round 3 and by only one opponent, rewarding yourself and a single opponent the maximum of 3 points. Likewise, if you think you know what an opponent's sculpture is and you believe nobody else does, you may want to confirm with obscure questions that will confirm it to yourself but not give hints to anyone else... and then perhaps wait until the 3rd round to finally make what you believe is the correct guess.
How it Plays Out:
Like I said, if you have a group of 4-6 people that can laugh at each other and enjoy a light party game, then I think Cluzzle is quite a unique idea and plays out very well. People who love party games and have never heard of it often respond very positively to the game, from my experience. If you have people in the group that tend to take things too seriously, get upset for not winning, or harp on someone for not following the rules precisely, then you're better off to play something else.
I'd give it a solid 8 according to BGG's rating system: "A Very Good Game". Again, this rating is recognizing that it's a party game.