Penumbra on OS X

[Shoe]

Hi,

I recently reinstalled the Penumbra series on my computer through Steam. The game downloaded and installed fine. Whenever I start any one of the three games in the series the game loads, the text intro plays, the game goes through the developer splash screen progression, and when I end up at each game's title screen there isn't any text displayed. I end up stuck looking at each game's title screen, listening to each game's (fantastic) intro music, with nothing to click on to allow me to play the game.

My computer is running Maverick's 10.9.1

2.4 GHz Intel Core i5
8 GB DDR3 Ram
Intel HD Graphics/Nvidia GeForce GT 330M

As far as I can tell all of my software and drivers are up to date.
My System Profiler is saying I'm running off the Intel HD Graphics, but I think the computer automatically switches to the GeForce GT 330 under heavy GPU demand. (?) I have tried deleting/re-downloading each game.

Thank you very much for any help you can provide.