Incredibly thoughtful and mechanically near-perfect, Celeste marries impeccable game design with a touching and relatable story in a way I've never experienced before. It's simultaneously an excellent platformer and an engaging meditation on the perils and methods of tackling depression and anxiety, and the fact that those two aspects are so naturally integrated is amazing.

On the surface Celeste is a retro-styled adventure about a girl scaling a mountain, jumping and air-dashing and climbing to solve the miniature puzzle on each screen, before moving to the next one. Challenging without being mean or exclusionary, the brilliantly expressive pixel graphics and an incredible genre-spanning soundtrack set the mood as you die again and again on your way to epiphany.

Early levels focus on avoiding spikes and teaching the basics (Madeleine has to touch solid ground to recharge her air-dash, and runs out of stamina if you climb too much), but the game builds a vocabulary of hazards and items over time so that later challenges are impressively complex, but players have the tools to overcome them.

Along the way Madeleine encounters various characters, who are well-written and funny, but the story told through gameplay is infinitely more memorable. Madeleine's self-doubt becomes a wraith that mirrors or mimics you along your path, for example, threatening to catch and obliterate you. An overwhelmed hotel owner self-destructively fills his beloved building with dangerous and messy detritus, to his shame.

The literal running and jumping of mountain-climbing blends with more fantastical allegories and concepts throughout, with many of the different characters manifesting their anxieties and traumas in different ways. So while it's a cohesive game about learning the various concepts and applying them in challenges of increasing complexity (and, if you like, you can totally ignore any narrative and just play it for that), on another level it feels like the cathartic work of dealing with and overcoming issues and insecurities.

The message — at least it seems to me — is that these things seem scary and insurmountable, but the best way to arm yourself against them is to pay attention, learn and understand. That these themes are never forced down your throat, coming through naturally in the settings, the challenges, and the cute exchanges between the characters, makes them all the more powerful.

Putting story aside for a second, it can't be overstated just how satisfying it is to play Celeste moment-to-moment.

Moving to a new screen is typically an intimidating experience, as you survey the challenge and wonder how on Earth you're going to overcome it. But by throwing yourself at the problem, little bits of the solution begin to emerge. Maybe the screen teaches you a new concept (that jumping from a moving platform affects your flight speed, for example, or that breaking a green crystal grants you an additional in-air dash), or maybe you just have to brute force your way through, repeating a sequence until you nail it perfectly.

Even in the most difficult screens — often the totally optional ones that challenge you to make it to a floating strawberry and escape with your life — I found that with perseverance I could make it through eventually. For those who find they can't, the game offers a judgement-free "assist" mode, which lets you become invincible, get more air-dashes or slow the action down. Doing this might hurt the metaphors slightly, but on the other hand there's never shame in asking for help if you need it.

Each of the eight chapters is visually and aurally diverse, filled with its own themed concepts and gimmicks, and while there's generally a linear path forward you'll be rewarded for exploration and lateral thinking. Not only are there delicious strawberries to find, but each chapter features a hidden cassette tape that unlocks that level's "B-Side". In these, the chapter elements (and the musical tracks) are remixed, challenging you to absolutely master the concepts you learned earlier. These stages sucked me into a zen-like state of platforming as I died literally thousands of times, but as with the main game it never felt unfair.

Even after playing through the game I haven't been able to stop returning for its cheeky secrets and challenging B-Sides, listening to its incredible soundtrack and thinking about its world. Developer Matt Makes Games — which you may know from the excellent battle arena game TowerFall — has delivered something very special with Celeste.

Celeste is out now for Switch (reviewed), PlayStation 4, PC and Xbox One.