Considering that this film is nearly 80 years old, it still stands up to today's exacting standards, yes some of the effects are a bit dodgy and really the stop motion that they use is dated and you can see the strings and you can tell how some of the effects are done but overall you have to remember that these effects were done in a different time period when things were done properly.
Reading up after watching this film this was actually a risque film, at the time this was made there were little to no rules about what you could show on film. Reading the history of the film from the cuts that were made to being restored it is a snap shot of where we have been with films. Overall this film is excellent you care about the characters and Kong who is the star of this film you care so much about what is happening to him and even though you know the end and you know where it is going you still hold your breath while he scales the tower.
I would say that this is a five star film that everybody who cares about film should at least try and watch once, it is also good if yo have seen the Peter Jackson film from 2005 you will see where he takes lots of his inspiration.