You star as the titular Astronut, with the straightforward goal of hopping through space between celestial bodies like planets, stars, and more. Whichever space object you land on, you’ll instantly start spinning around as you follow its rotation. Along the way, you’ll collect star shards and powerups. Your goal is to navigate ever higher (deeper?) into space, until you reach each level’s finish line.

All this planet hopping requires just two virtual buttons: Jump and Boost. Jump’s functionality is obvious; it’s the button you use to hop from planet to planet. Boost provides extra oomph, which you can use when you’re floating helplessly in space, or to power through aliens who seek to cause you harm, or just for a brief burst of speed. This isn’t Mario’s B button, though. You need to give Boost time to recharge each time you use it, so strategic boosting becomes a necessity.

Landing on planets is easy, and you can hang out on them as long as you’d like. Other celestial objects aren’t so patient—stay too long on a black hole or Sun-like star and you’ll suffer the consequences.

Beyond earning points for general progress and collected star shards and the like, you also earn bonuses in Astronut for successful hang time. The longer you float upwards without landing on a planet or crashing into an alien, the more you’ll score. Often, you’ll find that you need to propel yourself up into the unknown—the dangers and plants that await you are off the top of your iPhone’s screen—so you leap and hope for the best.

Technically, Astronut is a free download. But once you’ve blown through the first four levels, you’ll likely feel a strong compulsion to pony up $2 for the in-app purchase of 20 more levels. That’s because the game is a perfect iPhone time-waster. It’s addictive fun, and behaves well as a multitasking, state-saving iOS citizen: play for a moment, get back to work, and you can pick up your game hours later—just where you left off.