Orbient plays out somewhat like Katamari Damacy in space. You're a planetoid and you float around absorbing smaller planetoids to get bigger. As you grow, the other celestial bodies change color to indicate whether or not they're absorbable. Unlike Katamari though, only the next size up of planetoid will allow you to grow; smaller ones will just be absorbed for no benefit. However, that's where the titular orbiting comes in: Your end goal in each level is to get big enough to get the sun to orbit you, but along the way you can also get smaller planetoids to orbit you by drifting near them. Each level also has a moon to go after as an added challenge. With each added satellite, the game's minimalist music builds and grows more complex (although, unfortunately, capturing the moon resets it all to unique moon-orbiting music). Getting all the moons will unlock extra difficult levels, while having other planetoids orbiting you just nets you extra points and lives. Each level tracks your best score and time, so high score seekers and speedrunners could find added replay value there.
So that's the game's goal, but the way you control your movement makes Orbient even more unique. Rather than just flying around wherever you want, you can only influence your momentum by pressing A or B to either draw yourself in or repel yourself away from nearby planets according to their gravitational pull. This creates a somewhat slow-paced, but satisfying and challenging method of control. It's also possible to lock into the orbit of a larger planet by drifting past it, allowing you to easily move in and out within its orbit and then break free at just the right angle to slingshot to your next destination. Orbient's movement and controls work well almost all the time, but in situations with many surrounding planets, it can be hard to predict which direction their gravity will end up pushing or pulling you. Drifting into a larger planet or object will make you bounce off and lose a life. Even when it's difficult, the leisurely pace and indirect control method make playing a generally relaxing experience.
The Final Word:
If you haven't played an Art Style game, or even if you have, Orbient is the one I recommend most. It's fun, unique, challenging, and has a ton of levels. The gravitational controls work well almost all of the time. For being called "Art Style", I do think the game's visual and audio art direction could've managed to be a bit more appealing, but they aren't bad and get the job done. If you like chill, but tough, slow, but precise games, Art Style: ORIBENT is for you. It's pretty darn great and deserves a bit more recognition.
For a similarly chill downloadable game with lots of content, check out Knytt Underground!