Cannot for the life of me get this to start up

[Sniffkill]

It'll say "Preparing to launch..." then that window will close, then nothing.

I've tried both of these:
http://forums.steampowered.com/forums/showthread.php?t=1620666
http://forums.steampowered.com/forums/showthread.php?t=1415433

If it helps at all, here are some specs:
ATI Mobility Radeon HD 5650
Intel Core i5 CPU M460 @ 2.53GHz
64-bit Windows 7 Home Premium
4GB DDR3 RAM

Also, for some strange reason whenever I open it up my screen turns to a darker, slightly purplish color and doesn't go away until I put my computer in sleep/restart it.

[DavidtheDuke]

New update today, same as you until it works now (at least the menu, haven't tried the rest of the game). The update didn't specify what it did, but I'm really curious as to what.

It'll say "Preparing to launch..." then that window will close, then nothing.

I've tried both of these:
http://forums.steampowered.com/forums/showthread.php?t=1620666
http://forums.steampowered.com/forums/showthread.php?t=1415433

If it helps at all, here are some specs:
ATI Mobility Radeon HD 5650
Intel Core i5 CPU M460 @ 2.53GHz
64-bit Windows 7 Home Premium
4GB DDR3 RAM

Also, for some strange reason whenever I open it up my screen turns to a darker, slightly purplish color and doesn't go away until I put my computer in sleep/restart it.