I'm not sure it was enough.
It doesn't exactly start well. A bad model shot, and two old geezers badly acting as some down trodden slavers. The script also gives a lot of time to K9, but doesn't really do much with him, other than to distract Baker. Noticeably this is the first K9 heavy script I've watched, and I'm glad he was kept out of the loop so often.
The only thing keeping it even vaguely watchable are Baker and Ward's performances who are both on fine form. In fact I think I've finally figured out the Fourth Doctor. The manicness you see so much of in Tennant and Smith are the Fourth Doctor personified. He's the version that takes that aspect the furthest. Oh, it's present in Two and later in early Seven but Baker's incarnation rules with it. It’s not surprise this is the era that embraced the humour of it all.
As I revealed talking about 'Destiny of the Daleks' that's what finally clicked for me as I watched 'Nimon'. Doctor Who has completely embraced the idea of comedy episodes now, and it's pretty clear that's what's happening here. Unfortunately, it fails absolutely. It has an awful script and dialogue. The big human bad of Soldeed is atrociously acted and is almost pantomime in performance. And then there's the Nimon.
Never mind it's an awful costume. It's also a poor, and obvious pastiche of the Minotaur myth, with people heading into a maze that keeps changing and guarded by an alien that is basically just a Minotaur. There's not even any attempt at coming up with a unique angle on the design, or even an explanation for it. It's quite possibly the laziest I've ever seen Doctor Who. Though the idea that the Nimon are intergalactic locusts is a bright point in the serial, even if much isn't done with it.
Back when I watched 'City of Death', I wasn't keen on our Time Lady. She felt like the concept that gave birth to Captain Jack and River, that of a fellow traveller that knows nearly as much as the Doctor, who was taken too far. In 'Destiny' I rabbited on about how this new incarnation was very much shown as an equal to the Doctor, and it worked really well because for the most part the two of them meet up, discuss a couple of things then split up and go cause chaos separately. In 'Nimon' that's taken a step further with the Doctor relegated to attempts at humour in the Tardis with K9 while Romana herself gets the role generally given to the Doctor.
It's Romana that gets stuck on the transport ship and teams up with the sacrifices. It's Romana that first meets, figures out, and then forestalls the Nimon's plans. The Doctor only really comes in after the halfway mark and starts bumbling about. Now he does bring the story to a conclusion, but it's Romana who sets it up, even getting a survivor from the Nimon's last target to help at his end.
While all of this behaviour bugged me in 'City of Death' here it really works. Don't get me wrong, that the Doctor fannies about in the background doing next to nothing far half the serial is complete nonsense, but Romana does a good job as a stand-in. I think the part that really bothered me was in 'City of Death' Romana is almost working at odds against the Doctor because she knows best – and is tricked by Scarlioni – and as a result was an obstacle for the Doctor. Here she's proving why that's even possible, because she's just as capable.
However, despite how Romana comes across, 'Horns of Nimon' is quite possibly the worst Doctor Who I've had to put up with so far. It's certainly worse than 'Inferno' that stretched it's decent concept out beyond credibility. Maybe 'Stones of Venice' comes close, but that at least has something interesting in the premise, even if it was badly told.