Ok, this is just a daft Victorian action-adventure film with Doug McClure as the dashing explorer ably assisted by Peter Cushing (delivering a very similar style of performances as his "Doctor Who") as the boffin who designed the ultimate boring machine to travel to the innards of the planet. Once there, they encounter slaves ruled by a race of giant, angry looking, telepathic penguins. Based upon an Edgar Rice Burroughs fable, the effects are pretty dreadful and, indeed, so is the whole thing. It's isn't rubbish, though - and was a perfectly entertaining film for kids when I was 9!