Little green ball, what's up? You need to get to the other side of this puzzle, touching all the stars along the way? Sure I can help, stand aside, little one.
That's the premise for Space Physics, a neon-bright physics game that challenges you to draw bridges, cogs and (by combining cogs) slingshots to get your little green friend to roll over several stars spread out across each level.
At its most basic, you can simply draw a line between two platforms, then roll your ball across the bridge. Touch a star, and that's one down.
In more complex levels, you'll need to draw circles, either in open space (creating a wheel) or attached to a platform (creating a rotating cog), to get your ball moving in the right direction. Set up your cogs just right, and a pair will create a virtual slingshot, propelling your ball across the level in crazy-quick fashion.
Best of all, there's no one right way to solve each puzzle. Take your time, experiment with your drawings, and interesting things happen. Unfortunately, drawing specific objects can be challenging on older-generation Android devices with smaller screens. It might take several tries to get the game to understand what you're trying to draw.
When purchasing the full version, be sure to grab the Pack for Space Physics. This is a content pack that you can install right to your SD card to lessen the impact on most Android phones' anemic internal storage.