Once you have completed all the given goals, you will be awarded with 3, very
shiny stars.

Because the goals are important in completing each level, you should always
study them first and understand the task. You do not need to complete all the
goals in one time. Bad Piggies is designed in a way that you can complete 1 or 2
of your 3 goals first then replay the level later to complete your third goal.
So don’t worry, when you get the hang of the game, you will know which goals to
complete first and which ones later. A few examples of the goals can be found
below.
Examples of Goals in Bad Piggies
Pig: The most basic goal, and one that you’ll find on every
level. Simply make a contraption that will get the pig to the finish line.
Doesn’t matter if it’s slow or messy – as long as your porker gets there.
Star crates: On levels with this goal, one or more star
crates will be placed within the level. You’ve got to collect them and then
reach the finish to achieve this goal.
No breakages: You’ve got to reach the finish line without
your vehicle crumbling apart and without wheels snapping off mid-journey. Use
dependable metal tools instead of wood to secure this goal.
Stopwatch: You need to get the pig to the finish within a
specific time limit. The time is shown on the icon, and a timer will appear in
the top-right-hand corner on levels with this goal.
King pig: On some levels, you’ll have a giant pig that takes
up four spaces on the grid. You’ve got to ferry this monster porker to the
finish to score this goal.
Object restriction: To get this goal, you’ll need to hit the
finish line without using the tool that’s shown on the icon. Could be a
generator, a specific type of wheel, or a TNT crate. Your guess is as good as
mine. May be better.