Yes you can. Go to 1-player, select story, pick out the story and act, and then the level.
no
It should work.
No, but you can do 3 player multiplayer.
In Lego Indy 1 there are 18 and in Lego Indy 2 there are 90 levels made for you to play through. I am not including the made up levels which you make this answer is based on everything expect DS how ever there are 18 levels in Lego Indy one on DS it is not the same with Lego Indy 2.
play the survival mode or skeleton storymode
By beating them.
Yes. The game and the DS, however, are $$$.
Go into Gringott's bank where you have to learn how to build levels and play bonus levels.
There are 20 levels on Avatar Prom but you can play even if you finish them all.
You cannot walk there, but you can play levels there if you can continue the story-mode.
Play the Greivous campaign and finish Greivous Intrigue
It is called junkbot. you can play on lego.com.