There is 2 parts to lego star wars.
First is complete all the missions. 2nd is going back through all the levels and find all the secrets. (you cant do it straight away because you need different characters that only unlock later in the game)
I completed all the missions in just over a day.
Game is fun, and the cut scenes add a good comedy element, but the game just does not last long enough.
You can have adaptive ai on it, but again that does not make much difference to how long it would take to complete as you never run out of lives. You collect studs that are used as currency to buy unlocks (weapons, characters, etc). When you die you loose some of the studs you have found and when you have no studs left you still don’t stay dead.
I am glad i did not pay £30 for it.