I'm on level 2.
Update: Okay, a bit more data.
The puzzle is really to figure out what the puzzle is. Once you do that, a few jumps will get you to the answer, which is entered in the password field, in all-lowercase without any spaces.
I might give more of a hint on the first level if lots of people get stuck.
Update 2: Now on level 10. These remind me a bunch of the kind of puzzles that get used at the Microsoft PuzzleHunt. You get something, and then you have to figure out how data is encoded in it. Some of them are very easy, some are hard.
Apparently, the author is Thai.