The 1.3 version of prototype4 for Mac is available as a free download on our website. The unique ID for this app's bundle is com.sebastianvolland.prototype4. The application is included in Games. This free application is developed for Mac OS X 10.6 or later. The following versions: 1.3 and 1.2 are the most frequently downloaded ones by the program users. This free Mac application is an intellectual property of Sebastian Volland.
From the developer:
Prototype4 is a classic arcade space shooter, featuring intensive particle effects and retro sound effects.
You may want to check out more software for Mac, such as Laser Dolphin, Lugaru or Marathon, which might be similar to prototype4.