If you are the sort of person who can get a kick out of a very bad movie, then I highly recommend this one. If you aren't, stay away. This is an astonishingly cheap-looking movie, and at times you may find yourself wondering if it isn't just a prank someone is pulling on you. The most positive comment I can make about it is that the people responsible seemed to realize that it was super-low-budget nonsense, so there is at least a sense of fun here.
But this is as amateurish as it gets. Their idea of giant killer mushrooms are simply guys covered with beige colored sheets with what looks like trash can covers on their heads. It's obviously not meant to be taken seriously (to say the least), but even with that disclaimer you'll find yourself shaking your head at the awesome cheesiness of it all. Or laughing out loud frequently, as I did.