It's been a while, but you must rescue all the kids in each level where you start to rescue a kid. You can go through the game without rescuing them, but once you rescue one, you have to get them all. The reason for this is those map pieces you collect.
Once you make it so far you'll come to this vast lava pit with monsters in it. You need to use your pistol or dynamite to kill the monsters which will make a bridge for you to cross. Make your way through all the little islands until you come to the one at the top which has a big statue of Kali on it. Here is where you collect the Sankara stones. Head to the right and go through the door there. Now here is where the rescuing kins thing comes in place. If you have not rescued any or have rescued them all, you will be shown a complete map which marks the spot as to where the exit to the level is. Copy this down, you need it!. If you have not gotten all the kids, an incomplete map will be shown, hopefully the part that reveals the exit will be there.
This next part is tough. You must make it to the hidden exit for the level, that is what the map is for. There will be a kid to rescue there as well. When you rescue him, he will give you a red arrow pointing in which direction the exit is. Throw some dynamite there and the exit will be revealed. But, that's not the hard part. The hard part is that you must NOT die in this level. If you do, you will no longer have the 3 Sankara stones with you. They will be placed randomly on the level inside of the big skulls. You must recollect all the Sankara stones before exiting the level.
Now you are on the cliffs. You have to do a lot of swinging across large gaps, while being attacked at all times. When you finally get to a fork in the road near the top of the mountain, take the path
on the right, where you will finally be able to swing over a chasm to the exit door.
I think the bridge is next, just make your way across. Mola Ram is tossing burning hearts at you, while thugees and birds attack from every direction. Reach Mola and the brige is cut where you have to climb up the rope ladder. If you reach the top, Mola Ram simply disintegrates and Willie and Short Round, are waiting for you at the top. After all that, you have completed INDIANA JONES AND THE TEMPLE OF DOOM for NES.
Hope this helps.