Celeste is really really good and I love it so much because it was a demonstration of the fact that a ton of things people thought were not compatible were. You can't put accessibility options into a game billed on difficulty. You can't make a story heavy narrative game while still being a hardcore platforming game—the story people won't like the difficulty and the mechanics people will skip narrative. Hardcore gamers hate female protagonists, and they won't want to play as girls.
And all of that was wrong and didn't matter. Celeste is a "hardcore platformer", see. Not in the sense that it is hard, but in the sense that it focuses less on combat or battles and more on very difficult, precise platforming challenges that demand good play, thinking, planning, and high execution skills. Like Super Meat Boy. But of the games of its type, Celeste is probably the most accessible. Not just because it has accessibility options designed to make it possible for even people who have disabilities that would prevent them from playing the game from completing it, but also because it is very cleverly designed. It's good at teaching players, and at keeping new players from becoming intimidated. And while challenging, I wouldn't describe beating it as some privilege for the talented few. I bet all of you could beat the main game (there was an expansion that... is harder to get into and much harder to beat. But the main game is very completable) without being too frustrated. So if you came for the story, you will get an ending.
But if you came for the challenge, you won't be disappointed, because Celeste gives you control-breakingly hard content to play as optional content, for bragging rights (you must, alas, complete some of this to get to the expansion). Most obviously, Celeste has collectible strawberries scattered throughout its levels. They're hidden, locked behind extra hard platforming, or both—but don't worry, the game helps you hunt down the strawberries you missed if you want them all. Then, there are blue hearts, ususally locked behind cryptic puzzles, and finally there are tapes, which are locked behind nasty platforming challenges. Collecting a tape unlocks a B-side for the level, which is much, much harder. Beat every B-side and find their hidden collectibles, and you can unlock C sides.
It's so so brilliant. Just... go play it.