Yeah, unfortunately Gamemaker does that with 4-directional movement if you don't specify what to do when 2 buttons are pressed at once. (with older versions at least, don't know about studio)  I'm used to it by now so I didn't think about it.  Oh, but for the second level, you have to use your pause ability to walk through the line of walls to not be spotted, like a bridge of sorts. Also, I mention this later, but I included room skip hotkeys (9=previous; 0=next) for debugging, but left them in if someone's struggling with a level.