I think it's enjoyable taken entirely on its own term but pretty singular and unforgiving.
Yeah, it's surprisingly niche in appeal for such a high profile game. I'd be interested to see the numbers on players who bought it vs the percentage of them that actually persisted with it for more than an hour or two. Even the 'easy' mode seems unreasonably difficult to me compared to most games of the same genre, and also comes with a fairly patronising disclaimer attached to it - always a good way to turn the player off I find...
There's a whole wider conversation about game difficulty going on at the moment, but from where I stand I don't think there is really a justification in this day and age for making a game with such a deliberately forbidding difficulty curve beyond a kind of elitism. Not every game has to be universal in appeal, but a talented developer can surely make a game that can cater to and offer
some kind of experience for a range of ability levels, at the very least to ensure that a large number of players don't walk away feeling like they've wasted their money? By all means, ramp up the difficulty, but maybe ease players in with a handful of slightly less demanding stages first?
Even with Hollow Knight - a game I strongly disliked, in part due to its difficulty - I felt like it at least
had a difficulty curve and I was able to play for a few hours, and could have certainly got a lot further still had I been enjoying the game more.