The Great Pyramid was the tallest man-made structure in the world for over 3,800 years. Going up and down all the time must have been a chore for ancient Egyptians, much as you are likely to find it a chore going up and down this pyramid.
To get the second treasure from the left, you have to use the brick that blocks the ladder at the bottom as a bridge to escape.
To get the fourth treasure from the left, clear the three brick above and to the right of the left most mummy; if dug in the correct order, this will give you just enough time to grab the treasure and escape.
Some of the mummies must be released to get some of the treasure. However, get the first, second, and fourth treasures (from the left) before releasing any of the mummies. Be careful not to kill any mummies; if they appear to the right of the pyramid, you will be unable to finish the level. Also it is possible to release the mummies and trap them in one of the other chambers.