Jacob Olsen’s review published on Letterboxd:
I have always felt that when making a sequel to a successful original, the proper approach is to add more of everything that was good in the first one. Use the same tin, and just double the recipe. Sometimes this actually works.
In Back to the Future Part II the above method was used to the full, but they were taking on a bit too much in the process. Because the result is rather messy and indigestible.
And, let me start by addressing the most glaring issues when rewatching this today - the poor special effects. A huge part in explaining why the relatively few special effects in the original worked so well, is that they were - relatively few. And also quite simple. Many transitions were done simply by cutting to a new scene. In 1989, the technology weren't quite there yet to show flying objects in a normal (our) world. In the HD transfer, the large halos around artificial objects becomes very prominent. But that isn't perhaps the biggest problems this film has. Since we're now actually living in 2013, and the future world in the film is only two years away, a lot of other things seems hopelessly dated. Like telefaxing and matrix printers. This still exists in a world where flying is the everyday means of transport. So this film hasn't aged well.
So, it's the future sequences that fails, I must say, miserably. But in this film they take on a lot, we also get to revisit familiar scenes from the first film, played out from other angles. If I now remember correctly, this is the timeline of the film: 1985 -> 2015 -> 1985 (altered universe, parallel to the 'other' 1985) -> 1955 -> (1885), where the film ends with the promise of another sequel to come the following year. The ending is nothing but a teaser for the next film, a rather bizarre conclusion.
But the revisit to 1955 from the first film actually works quite well. Making Biff (Thomas F. Wilson) a more important character is actually a good call in this sequence. The Sports Calendar is also something that really can get you thinking - what if... and is a bit of a moral dilemma.
And it's never boring, of course. Silly, yes, and dated (some of it) but always entertaining. The method of doubling the recipe could perhaps have been adjusted here by reducing on the 2015 sequences, but that is just me speaking with hindsight. They wanted to go there, and I remember it working better, much better, in the theater at that time.