The Funhouse is one of the better slasher movies from this era. It has a great atmosphere and a good build, but there is one major problem with this movie: The buildup is way too long and way too slow. A big part of this movie is the carnival atmosphere, but the plot doesn't start until about 40 minutes into the movie and there are no deaths until about 45 minutes in. What happens in the first 40 or so minutes? Four teens walk around a carnival and visit the attractions. It was great for like 20 minutes, but it was just too long. There is just not too much going on in this movie, despite being one of Tobe Hooper's better directorial efforts.
The monster is hilarious. He flails around constantly and has this Leatherface-like scream that is so annoying and funny.
Tobe Hooper made this with a clear love for horror movies. There are so many references to classic horror movies like Psycho, Halloween, almost every early Universal horror monster, and others. For that reason alone it's worth checking out.