Each round there are four new shapes to place in each of the junk drawer compartments. Each compartment can be used only once per round.
Place the shapes to try to maximise your score as outlined in the goal cards.
The game continues until one (or all) player(s) can't place a shape. When each player has placed that shape (or passed) the game ends.
A game variation keeps the game going until the last player passes.
You will not have an option to pass if there is a shape you can play. If there is nowhere to place a shape you will not have any option other than to pass.
There is a user preference that will give you a help button which will indicate where a shape can be placed but the intention is that experienced players will choose not to use this. But it is there in a situation you just can't find a location for a shape.
The default option for placing shapes is to tap and click but this can be changed to drag and drop in player preferences. Drag and drop does not work properly on touch screens.