I too love Zagreus.
The ‘not a traditional multi-Doctor story’ complaint is utter nonsense IMO. There seems to be ‘received wisdom’ in fandom that multi-Doctor stories need to replicate The Three Doctors and The Five Doctors in terms of having all the Doctors join up and have an adventure. It was the same received wisdom which saw people getting their knickers in a twist over The Day of the Doctor and the 60th anniversary specials (especially Wild Blue Yonder).
But it’s nonsense. The Five Doctors is actually the only story where the ‘traditional’ multi-Doctor thing works - and even that is technically only four Doctors. The Three Doctors stick Hartnell on a screen for the duration.
The ‘multi-Doctor’ story fans think exists is really just a figment of their imagination and, let’s face it, how would anything beyond five Doctors even work narratively, especially by the time of the 60th. It’s ridiculous that some fans think that would even begin to work.
As for Big Finish. Well, they did a ‘traditional’ multi-Doctor story ten years later for the 50th - The Light at the End - and that drew a fair amount of criticism too - mainly for being too ‘straightforward’ as it were.
I think Zagreus is a brilliant way of celebrating a Doctor Who anniversary in a different way. Allowing all the then regulars to come in and play different parts is such fun and the story is all still tied into the Doctor and Gallifrey and the show in general so works as a celebration.
It’s an absolute joy to hear Davison, Baker and McCoy in their other roles all of which are really only one step removed from their Doctors. My favourite bit is Winkle’s Wonderland as I love Disney so a whole post apocalyptic Disney World is right up my street.
India Fisher holds the whole thihg together so well and we even get appearances from Nicholas Courtney, Elisabeth Sladen, Anneke Wills, Jon Pertwee (even if he’s almost unintelligible) and a springboard for the Gallifrey series with Lalla Ward and Louise Jameson.
And of course McGann is great.
Is it a bit long - maybe, but I’ve never felt bored listening to this as so much is happening across its three discs.
It’s all I can do not to go and give it another listen. It’s brilliant!