Don't underestimate the name of this scenario; Holland was a real fortress, and that's a historical fact!
You play a German attack division that invades Holland in May 1940. If you use your tactic very well, you may win, but if you try a brutal attack you will probably lose the scn....
Also, you need to combine an air- and ground-attack.
First build 3 paratrooper-planes before you attack!!!