Downloading Roundabout 1.0 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this Mac application is No Goblin. We recommend checking the downloaded files with any free antivirus. Roundabout for Mac lies within Games, more precisely Arcade.
From the developer:
Roundabout is a '70s B-Movie game where you drive a constantly revolving limousine! Pick up passengers, find secret collectibles, take on dangerous missions, and fall in love in an open-world puzzle adventure. You'll experience the seventies in the only authentic way possible: with full motion video set in the interior of a limousine.
You may want to check out more Mac applications, such as Pinna, which might be similar to Roundabout.