Airtight Games' physics-based puzzle-platformer Quantum Conundrum is the latest title added to the PlayStation Plus Instant Game Collection, the PlayStation Blog announced today.
The game, originally released this summer on Steam, XBLA and PSN, will be free for PS Plus members after the PlayStation Store updates tomorrow, Nov. 13.
PlayStation is also offering Amanita Design's adventure title Machinarium to PS Plus subscribers for $6.99, 30 percent off its original price. The point-and-click puzzle solving game was originally released in 2009 for PC, and has since been ported to PS3, iPad, Blackberry and Android, with a Vita port on its way. The storyline follows a group of robots as they try to stop an evil organization from blowing up their city's central tower.
PS3 owners without PS Plus can sign up at $17.99 for 3 months or $49.99 for a year's service.