Recent investigation with some helpful users has shown that our current Unity Version 4.2.0f4 is making serious trouble on some users systems, e.g. the game crashes without any usable information, without showing even the intro, just a short flash of a white screen, then something about a crash folder that was created.
On the computers of two users this was caused by corrupted fonts installed in their windows fonts directory. After removing them, the engine started as expected, and they can now both play the game in its current state.
If - and only if - you are experiencing this since about Patch 1.18 (where this problem was introduced by our upgrade to Unity 4.2, which solved different other problems), please try and check your fonts directory with one of the tools available. This is not intended to sell *any* software, please don't buy anything unless you really need it for something despite this onetime font check, but the programs below helped these users fix this specific problem:http://www.insidersoftware.com/FA_win_details.phphttp://www.proximasoftware.com/fontexpert
You would only need them to "find and fix corrupt fonts".
We hope that Unity will soon fix this problem of the engine themselfes, we don't know if it is already fixed in 4.2.1, the current version we are updating to for Version 1.27, give the above a shot if you run into problems.