Fez would be close to my favourite game of all time, it's not often that you come across something, that resonates with you to the degree that it has with me. To me playing it is an experience, I would place it in a similar category to Outer Wilds, Hollow Knight & Elden Ring amongst others. Every so often a game comes along where the final result is greater than the sum of it parts.
At it's heart the game primarily revolves around puzzles, within the framework of a platform game. However, the platforming elements are purely a means of traversal, there are no enemies to fight, nor can you die. The focus is primarily on the puzzles, they range from fairly simple early on to nigh on impossible to do on your own in the endgame. I think that the sort of people who would only look to a guide as a last resort, are the ones who will get the most out of it here. The major aspect of the gameplay loop, the perspective shifting is difficult to explain, but one of the most brilliant concepts I have come across. The z-axis only exists whilst perspective shifting, watch a video or try the demo available on various platforms, once you begin to grasp some of the finer implications it's a thing of beauty.
A simple but vibrant and charming art style, the characters (especially the player, Gomez) have many subtle but very expressive ways of conveying emotion and I can't help but be drawn in. I would also say that the soundtrack is one my favourites of all time, quite chill & melancholy in general, with happy & darker undertones at times, to me it really conveys the experience of exploring on your own, the loneliness of being amongst the very few who are aware of the true nature of the world.
It's definitely not a game for everybody, but when it clicks, I don't have words, if you know, you know.