'Cooperative' and 'puzzle' are two words that I generally don't associate with great gaming experiences; however, Sprawlopolis deserves attention from anyone who values analog gaming, strategy per cubic inch of game box, and/or city planning. This is a very cool experience.
The first reason it's cool is that - consisting of 18 cards and a little wallet to hold them - it's a hyper-portable game. I love games that have plenty of decisions packed into a small form factor - and this one delivers in spades. It can go anywhere, and can easily be played while you wait for your meal - the 'play area' takes up approximately 12"x24".
The second reason it's cool is that it's very different every time - each of the 18 cards has a side that has a victory/points generation condition - you'll have 3 very different objectives each time. Not 'different' like a Sagrada 'points for the color blue' versus points for the color green,' but rather substantively different objectives related to the way you design/layout the city that you're planning.
And this for me is a treat - as a city planner by training, I'm pleased with decisions about optimal layouts to achieve given objectives. In some ways, this is a typical tile-layer I suppose; however the variety of objectives makes it feel very different each time. It is extremely engrossing, as all players collaborate to optimize the score generated by the played card - and there are a relatively limited number of possible locations and orientations, so it doesn't lend itself to terrible analysis paralysis.
This is a winner for someone who might need to entertain herself or up to say 3 total (IMHO) players on the spot, without a lot of prior planning - definitely pack it on your next outing without another thought.
(Note From Alex: As someone who is currently traveling in Argentina as of the writing of this review, can confirm that Sprawlopolis travels very very well. And plays just as well on an empty bed as it does a table. With a small form factor, all of Dan's points above, and a few expansions in case you needed more variety, it's really a great game worth having)