First off, think of Race The Sun as a mobile game, but magnified onto a larger screen. There is no story, no dialogue: just the simple objective of don't die. That includes getting as far as you can while the sun is still up, as you are a solar powered aircraft (hence the title, Race the Sun). So pretty much it's a time trial, except instead of numbers on a timer, it's a natural time limit. Controls are intuitive and simple, like many other platformers. As you progress in the game you'll get more abilites and things to collect while dodging huge rotating boxes and manoeuvring through narrow tunnels. There is also a level designer, although that was too complex for me to figure out how to use, and I decided just racing would be a better use of my time.
Overall, this is a fun, action packed platformer with beautiful minimalist graphics that brings a new dynamic of racing the Sun until it sets. Highly recommended, but not for its price. I bought it for $2 while it was on sale, and for that it is more than worth it. However, $10 might be a little on the pricey side for a game with its amount of content.
Regardless of the price, I rate it 8/10 for what it is.