A pretty cute experience overall.  It definitely had me laughing at times but you can tell this comedy simply comes from a different era.  Sure, it is clearly minded for a younger audience - the Master spending hundreds of years trudging through the sewers is a good example of that, but it also has a ton of jokes that really wouldn't fly for an all-ages audience these days, either.

In any case, it's great seeing Rowan Atkinson do a genuinely good job as a Doctor actor.  With the other regenerations along with stuff like McGann, John Hurt, and even the Shalka webcasts, there's definitely this sense in the fan community that there's a series of "lost Doctors" - actors who very likely would have had the role in the 90s during the Wilderness Era had the series not been cancelled.  I think, even though The Curse of Fatal Death is clearly a silly parody, they do take the source material just seriously enough we can get a real sense of what that show might look like, what sensibilities it would have had, and, given Moffat wrote this, a real sense of some of the aspects of production that would define Doctor Who in the future.  Any Doctor Who fan who really digs this sort of material should watch this at least once - it is a very interesting experience and short enough it doesn't overstay its welcome... at least not too much.

• The Doctor explaining (or failing to explain) crazy concepts to the companion
• The Master allying himself with the Daleks
• Good use of time travel (as in the "I anticipated your journey back in time" moments)
• Regeneration scene(s)
• and even a twist that brings an unknown element to something already established in the lore
  (as is the case here of the Doctor going beyond the regeneration limit, which back then was something we didn't know how it would happen or what effects it would have - for all intents and purposes, in this reality, when the regeneration limit is exceeded, the Doctor regenerates into a gender-inverted body apparently).

The Curse of Fatal Death is delightfully fun and very funny. From what I heard about this special, I was expecting to hate it. While some of the jokes might have aged a bit poorly or not be as "PC" as some would like, I still found them mostly harmless and funny. I'm glad I waited until after watching Classic Who to watch this, as it utilises a lot of tropes as basis for jokes and gags. It's also interesting to see how much this clearly influenced the revival, from the golden glow of regeneration to a female thirteenth Doctor.

one of the best specials ever made

This is cannon.

I refuse to believe otherwise

Absolute peak