It's not so bad. Yes, the production values are lacking. Yes, there are abundant plot holes -- however, for a Poverty Row war movie from the 1940s, the movie is actually not half bad. While there are numerous shots of stock footage and people walking in to poorly painted curtains doubling for the winter-bound grandeur that is Norway, the acting is better than one would expect in a movie of the genre. The writing seems to be a half-tick better than the average fare of the time and genre. The fellow playing the Nazi commander isn't the normal "one note" evil Nazi so often seen both then and later in such movies. The fellow playing the chief commando on the raid is fairly effective, if not entirely believable in the part.
All in all, I recommend it for those who are World War II buffs and have 70 minutes to kill.