In Havanna you need to acquire victory points, by constructing buildings, available on the table. To take a building you got to fulfill the displayed requirements and expend the necessary money, workers and resources.
The core mechanic revolves around 13 cards for each player, of which only 2 are played per round. But in addition to the card function, the numerical combination of cards played is important(e.g. a card with a value of 3 and 4, result in the value 34) as the player with the lowest combined number acts first.
So not only is the start player constantly changing, but
it is also a possible, that a planned action cannot be taken, as another player has already used the same exclusive action.
Furthermore not all of the available buildings on the table are ripe for the taking, as only the ones on the right and left hand border of the 2 rows of buildings are available for selection.