I managed to complete the level using Chrome on Windows 7.
Couldn't even get past a white screen when trying to run on Firefox 4.0 once it indicated the game was loaded. I then updated to 8.0 and as soon as I got up the stack of crates and made it about 1/3 the way across the platform with the second black germ, I too got the same screen discussed above.
So I went back to Chrome and played it through again. Great start!