A friend recommended Lulu Blue's Galactic Donut Dance: GiDon Donut to me, an indie game in which you control a shooting star as it flies through the sky and dives through rings of light that look like space donuts. At just $2.42 I thought it would be worth a go and was certainly not left disappointed.
The main reason I was attracted to the game, besides my friend's recommendation, was the central gameplay mechanic, which is based on inertia. It's surprisingly rare to see inertia used as a central gameplay mechanic, but when you think about it it's a brilliant concept.
On each level, your objective is to crash through numerous rings and then reach the goal as quickly as possible. You have quite a bit of thrust, but each impact slows you down, so you must plan your path carefully and make sure you have enough momentum to reach the goal. Once you've beaten a level, you can go back to it and try to beat your best time.
It's a novel and addictive game that should appeal to both so-called casual and core/hardcore gamers alike, and is well worth a punt at such a low price point. Be sure to let me know what you think if you do decide to try it out.