I have a friend that has it for XBox, so I'm not sure if it works the same way as PC thought. Anyway, from what I've played and seen my friend play, the time doesn't seem to make much of a difference.
That is, if the XBox is just like the PC version (which I believe it is). You should have plenty of time for jumping (jumpings fun... and it's also fun to slaughter the random people as well... XD).
I forget if it plays online or not (as the PC version has never worked on my computer), but I'd guess it would work the same way there was well. Of course, someone will probably come across with a more definite answer.