Unless I missed it, I'm the first one to mention Celeste, huh?
I literally don't know many more games that feels as good to control as Celeste. And controls are VITAL to games. Just the mechanics are so simple, with the grab and the dash, but the movement of platforming, the momentum, the weight, the friction.. Absurdly well programmed, and it raises this interesting point of immersion, and how you become a character and exist in a world, and Celeste is such an incredible example in how you accomplish those things through just well programmed controls. You ARE Madeline, as much as you're there, on the cliff, as her. It feels so real, and so palpable.
There's literally zero complaints to raise, anywhere, about the level design, I personally just view it to be all across the board perfect. Not a millimetre is out of line.
Madeline is instantly iconic with her long red hair and blue jacket, and all the side characters vibe so well with her and the overall aesthetic theme of the game. The dialogue noises are just perfect, and they convey emotion in a way that fits so well with the colourful, expressive character portraits. The soundtrack is amazing, and there's so much synesthesia in how its being gelled together with the pixel art - it's like.. when you see the game in motion, you can hear that music in your head, they really fit that well together.
Making the mountain a metaphor for overcoming your inner demons and anxiety was a stroke of genius in terms of contextualising a story hook into the pure platforming experience. And it's done so, so, so well. Without going into spoilers, it just follows that theme down to the last drop and really creates an arc that goes hand in hand with the gameplay just as well as the best works in the medium does it.
It's an interesting discussion, "best", or "perfect". Few of my top 10 games are perfect. Celeste, though? If you ask me, it's a perfect game.