Why is Pixel Dungeon so underground? To me, it seems basically like a turn-based souls game. I am playing this game for 2 years now (The OG Pixel Dungeon) and i still find new content, like its infinite.
I have a hard time with the controls and all the minutia of the different things you have to do to be successful. It’s not really as enjoyable as a souls game.
As a roguelike game, it is obviously too difficult for a game like Candy Crush Saga. In fact, the test mode should be guidized to reduce the difficulty and attract more new players.
Having a guided tutorial would defeat the purpose of a rogue like. The point of a rogue like is to learn about the game as you play, with the only thing getting upgraded as you retry is you. A guided tutorial shortcuts this, and while rogue likes certainly aren't for everyone, that doesn't mean that PD shouldn't be a traditional rogue like.
Sil is a roguelike with a built-in tutorial. It teaches you the basics of the game but leaves the vast majority for you to figure out yourself. It’s far more difficult than SPD (the only Pixel Dungeon variant I’ve played).
Pixel Dungeon is a rogue-like, those existed way before Dark Souls. There are even text-based games running in a Unix terminal, I think Nethack is one of the oldest, if not the oldest itself.
It's difficulty it's what makes the game so great. Unfortunately, the general public won't put the effort in to fully enjoy it. I found it by chance about 3 years ago and it's gotten me through some times. It's got more soul than everything else out there IMO. Doesn't matter of its underrated by the public. Those of us who know, know it's worth. It's made for us, not those who wouldn't appreciate it.
I'd guess a lot of people never play it because it seems too simple/boring. Those that do stick with it thinking it IS a simple game might get overwhelmed with resource management and optimizing their character and upgrades based on class and starting conditions. You have to rely on the wiki or a lot of trial and error and that can make people quit.