The Human Centipede - why is it a Thriller?

The Human Centipede trailer makes it obvious that it will be a thriller, through certain traits that it does e.g. in a remote area. There are two American girls in Germany for their first time, and they are trying to find a party but get lost and their car tyre gets punctured. During all this there is a dark solemn music which is going around, and the weather is rainy and stormy another obvious thriller trait, They find a house in the middle of nowhere, another thriller trait, and where they find a creepy mad scientist another trait to a thriller. In the house there are painting of Siamese twins, which is extremely weird, leading up to a twisted thriller. All these points signify the genre and are part of the codes and conventions of a Thriller.