I struggled through this, it’s pretty excruciating. The theme and style reminded me of old Star Trek episodes where they face god-like beings with childish minds (‘The Squire of Gothos’, ‘Plato’s Stepchildren’, etc.). I never cared for those either, and this has the curse of being more than twice as long.
For a large part of the story, the Doctor is kept separated from the others, not allowed to talk to them, or talk at all! The Toymaker even goes so far as to make the Doctor invisible/incorporeal, aside from one of his hands, so all he can do is continue to solve a brick-stacking puzzle set for him. Perhaps William Hartnell couldn’t make it into work that day.
While the Doctor gets distracted, Steven and Dodo have to play potentially deadly games against toys brought to life as real characters, and encounter fake Tardises on their quest to reach the real one. Each episode ends with a riddle for the next puzzle, so the kids watching at home can play along or something.
Learning is fun. This was not.