Gumnaam advertises itself as a horror thriller. Well. It's not. There are about 2 minutes that were really thrilling. Most of the time the movie was not as scary as it would have liked to be. But who cares?! I found it entertaining and I think if you understand all that is said and don't have to rely on subtitles you might even find it more funny, especially every time Mehboob as the butler is on screen. My favorites in this film were Helen and Pran. In many films they get only short roles, it was great to see them on the screen for so long - and even flirting :-) Of course Helen having several song-and-dance scenes is a BIG plus for Gumnaam. And the other songs are good as well. No need to add anything about Jan Paheehan Ho....!
Don't watch this film if you are against smoking and drinking... I've never seen so many people smoking in a film! And even the girls are "corrupted" into drinking alcohol. How shocking! ;-) But hey, if it results in a cool song, that's fine with me!
Gumnaam may not be the best film ever produced ever in Mumbai but it's definitely entertaining and has great music!