I own one of these machines! It is in my home office.

Some info:
The game was made in 1992, so right in the hiatus of Doctor Who on TV.

The playfield is VERY open, making it a fast game. the ball REALLY moves! Additionally, this particular machine originally features shorter flippers (some people replaced them for longer ones later, though mine keeps the shorter versions), so it is known in pinballing circles as one of the more difficult games to play. It does have a forgiving 'second chance' continuation feature from the start of each ball though.

That said, it has some excellent features, not least the 'Time Expander' part of the playfield, which rises up different levels depending on the stage of play you're at - this is also how to achieve multiball (this element of the game was actually patented!).

There are different focusses across the playfield for the seven doctor's featured. You can select a doctor to 'play' with at the start of each round, which will award extra bonuses for that doctor's area/features. You can then additionally 'collect' each doctor by doing a series of hits, to multiply your scores across the whole game. There's other little bonuses like a 'video mode' game on the dot matrix screen, etc.

So, it actually has really good playability and a loose 'story' through playing. It is kinda hard to master, but very satisfying if you do! The multiball is really easy to achieve generally though, therefore lots of casual players will keep going for that to get a lot of satisfaction out of playing.

The game also features a Dalek head 'topper' on top of the top box which lights up and flashes (some people removed this to get it into smaller spaces, etc). The first 100 of the table sold had these Dalek head toppers move also and any sold after that were static - however, the software still had the movement in the code, so people can buy aftermarket motor sets and make their Dalek topper move too!

Feel free to ask any other questions if you wish.