If the majority of readers don't get it, the dots are too far apart.
Writing is like humor, in this respect. If the majority of your audience doesn't laugh at your jokes, then you aren't funny.
Fiction is like humor in another respect: It is entertainment, and for entertainment to be "good" it cannot leave people confused and not understanding what was supposed to have just happened. They will go along with you for about 15% of the story, all (adult) readers know this is part of the deal and part of the fun: You get dropped into strange environment with unknown characters and have to get to know them. But the unknowns need to be clearing away, they expect that too. Nobody is going to read 50 pages if understanding is not trickling in as they go.
I think you need to be more explicit; your clues are too obscure. Your objective is to entertain, not confuse.
Another way to accomplish what you want is a twist. Readers can be satisfied (not confused) by being tricked into believing the wrong thing, as long as when the big reveal comes around (Nick is really Satan!) this reveal is consistent with everything that went before; and they can see that Nick being Satan was just as viable an explanation all along.
To me, the best twist ever is in The Sixth Sense, the clues of what is really going on are scattered throughout, from the beginning. They are on display, but the writing expertly distracts us from them by always making something else more important to focus on, when they are shown. So they slip by, on the first viewing, but are clearly all there on the second viewing.
You can do something similar, prove Nick has magical powers, but he blows them off as a magic trick; a little hobby he has, messing with people's minds. Same thing with mind-reading, guessing the names of the guy's wife and kids, a mentalist stage trick. And of course, a magician never reveals his secrets.
You need more clues. It is a narrow path you have to walk. On the right side of the path, with lots of clues, there are no surprises or unexpected developments, so the reader gets bored. The story is too predictable.
On the left side, there are not enough clues or resolutions. Too many surprises, too many unexpected developments. You are demanding too much attention and memorization from the reader, forcing them to mentally work at understanding, and that is not entertaining. So the reader gets frustrated, the story is too difficult -- Too unpredictable.
I think you are off on this left side, you need to add enough clues as to what is going on to keep the reader engaged, but still not knowing quite enough so they are still wondering how it will turn out.