The atmosphere gets unsettlingly cramped at times, though this doesn’t feel like an ideal narrative for the Doctor. The story begins in a peculiar way, as if segments are absent. We see the group of four already confined within the TARDIS, and their behavior is strange. They seem unfamiliar with each other – there's very little sense of reliance among them. Their time machine is out of order, and William Hartnell’s Doctor has suffered a blow to the head. Jacqueline Hill’s Barbara, Carole Ann Ford’s Susan, and William Chesteron’s Ian have to manage their disagreements, which occasionally erupt into physical altercations, in an attempt to understand what's happening. Is it possible that the TARDIS itself is responsible for the trouble? And if so, would that be a positive or negative development? The entire production takes place on a limited set, and this highlights the constraints of the camera work. Occasionally, this results in powerful close-ups, but frequently the camera struggles to accommodate everyone within the frame, with noticeable shadows from both the equipment and the actors. There’s some suspense present, but not enough real danger.

Source on TMDB