tl;dr - Audio Version: https://soundcloud.com/econaelgaming/review-racethesun
Race the Sun is a beautifully crafted game with an appealing aesthetic.
Sadly the great polish of game mechanics doesn't bring a similar level of polish of the game's design.
Race the Sun is an endless runner with an infinitely wide world and it disincentivizes lateral movement by making it dangerous.
The theme is that you're steering a solar powered glider and the sun is going down quickly, making shadows longer.
There are pickups that push the sun back up and give you a speed boost.
These pickups have a big ray that goes into the sky, showing where they are, but the draw distance is so low, that when you see them, you need to instantly do a full steer in that direction to get it and if there's an obstacle close to you forcing you to stay put for a second, you'll miss it.
There is only 1 level that is freshly generated once a day.
These things coupled together, mean that optimal play includes trial & error to find the optimal path that connects as many of said powerups and memorization of that path.
The game uses a progression via small achievements, similar to games such as Jetpack Joyride and these achievements unlock new game mechanics (powerups, game modes etc.).
Gating content behind achievements always means that most of those achievements are boring, so as to not hide a big percentage of content from players, so the game has lots of "Reach X amount of cumulative distance traveled" or "Crash X times" achievements. On top of that, the text upon reaching an achievement is a nihilistic "meh, achievements suck anyway and you're stupid for caring about points" type of "humorous" text.
I unlocked a harder game mode that has repeated the same ~20 seconds of level over and over. I believe it would repeat endlessly. Not appealing.
So it's still very beautiful and the controls feel nice, but there's not a lot of game behind it.