Like it says. Will the game run on this hardware? And how well?
OS: Mac OS X 10.10.1 (Yosemite)
Processor: 2 GHz Intel Core 2 Duo
Memory: 8 GB 1067 MHz DDR3
Graphics: NVIDIA GeForce 9400 256 MB
Display: 20-inch 1680x1050
You really don't want to even try it on that spec. I tried to play the Win version of this on a 2009 13" MacBook Pro with a similarish spec to yours:
2.53Ghz, 8GB Ram, SSD, 13" Screen at 1280x800, Nvidia 9400m 256mb but in Bootcamp (Probably WinXP at the time, could have been Win 7)
The results where not good, even at the lowest possible detail settings I was getting periods of 1-2FPS. Basically it along with games like LA Noire, Ghostbusters and others went into a "Unplayable on 2009 MBP" category.
That said on the same computer I did 130 hours of Dragon Age Origins and 60 hours of Divinity Original Sin at roughly ~10-14 FPS. Both at the lowest settings possible (apart from screen res).
Having just got a new computer I'm about to download TWEE 1 myself so I can finally play it :)