Not really enough money or effort put into this one. It appears that everyone thought simply that the presence of various 'freaks' Donald Pleasence, a bit of nudity and some man eating plants should see them through.
Actually this almost works, unfortunately Mr Pleasence is in particularly one note form and although the speeded up photography for the plants is fine the later costumes for those that have turned into half human, half plant are not half as effective. There are some decent moments and good ideas but it is all so uphill. Undeniably quirky, though and probably worth it for the fairground scenes.