TL;DR: Magnificent, unique (both visually and mechanically), and fun experience. Not "really" narrative-driven. In any case, one of my favorite games of the last decade for sure.

Simultaneously unique and technically impressive, this short and sometimes weird adventure is definitely one to try. Visuals are gorgeous, and often feel so inventive, I'd almost forget how much of the areas is procedurally generated. Similarly, the sound design follows through with quite enough musical variation and strong work with the non musical ambiance. There is some kind of story, but its content remains mostly unclear (I believe intentionally), which never felt problematic as it seems to exist more to give some dark, foreign, sci-fi vibe, than to act as the centerpiece of the experience. Good news: it all works perfectly.

Controls are fresh and simple enough to be understood regardless of the lack of hand-holding. On that matter, the tutorial is very basic, the controls being swiftly presented with texts and icons without a lot of explanation at the beginning of the game. The more in-depth intricacies, like how to break the sound barrier for a long time or to gain continuous speed in more difficult terrain, is left to the player to discover. Without any loss condition, this doesn't feel too big of a challenge, and the rewards come quickly as you blast through the sky, water, electrical clouds, even space. Really cool feeling. Also, considering the nature of the levels and some of the effects, the whole experience runs surprisingly well even at ultra settings across the board.

There is some replayability considering the openness of the controls and the extremely gigantic levels configurations, supported mainly in the form of a timer, coupled with related achievements (beating the whole game under certain times), as well as some other achievements that manage well enough to make me want to explore the levels and mechanics a bit more. I'm surprised there aren't similar timers level by level (unless I missed something?), but that's not a problem per say.

The only serious issue I can easily imagine many having with the game is its relatively short length (I finished the whole thing on my first try in under 2 hours). That being said, there's just nothing like it, and frankly, it's just such an amazing experience that I wouldn't care, even at full price. In fact, for an optimal experience, I'd strongly recommend playing the full game in one sitting, really just like a movie.

All in all, I wholeheartedly recommend this game!
10/10