Wishbone: It does. This happened to my son yesterday (and he's never logged onto Steam anywhere but on that specific computer). The popup window even explicitly stated that without choosing one of those options (upload to cloud/download from cloud) the game would not be able to start.
lukaszthegreat: which i agree is fucking annoying. not a deal breaker but still so stupid. give you option (without a pop out. a button in steam overlay is enough) but stopping you from playing it? needs fixing.
which it will be... i mean offline mode was broken in 2004 and that was fixed quickly.
There's nothing to fix. The current approach *is* the non-broken way to do it.
Essentially, Steam Cloud support means that your Steam client stores saves etc. on the Steam servers (the exact definition of a "save" depends entirely on the game developers, so if something like graphics settings get saved to the cloud, that is entirely the fault of the game developers, not Steam.)
When you first upload to the Steam Cloud, your client says "Hi Cloud, I have these save files here", and the server says "Okay, I'll store that in a box called revision 1 and mark it with the current date/time". This process gets repeated for subsequent changes to the save files, except the box is clearly labeled differently, and we still retain some amount of knowledge. Essentially, you end up with a chain of revisions, and if all goes well, any one of your computers will have files corresponding to a single point in that chain.
When you start the game, your client goes "Hey, I have these save files, do you have anything newer?" and then the server will either say "Nope", "Yes, here you go", or "Wait a minute, I haven't seen those files before!"
That last case is what happens when Steam pops up the conflict dialogs (Upload/Download/Cancel): something has happened to cause one of your computers to carry save files which aren't part of that chain. There is no correct answer on what to do: either action risks losing progress, and the user is the only one who has a chance of knowing what should be done. It's not possible to merge the two in any sensible way, so you
have to pick one or the other.
Let's say, however, that Steam let you ignore the problem. What's going to happen when you're done playing? It can't upload your new saves, because that might still clobber your progress. If it just leaves your current saves on the computer, then the problem still isn't fixed.
There are only three ways this could be different:
1) You could allow individual computers to not use the Steam Cloud - but if you start doing that, you're kind of removing the point of having the Cloud there to begin with
2) Remove all automation and have the user decide when to sync to and from the Cloud - and that introduces a long list of issues which ends up making it easier to copy the files manually
3) Allow multiple branches to exist simultaneously - and that's only going to confuse users in the end
Ultimately, you need *some* kind of conflict resolution, and postponing it will only make things worse - so the most sensible thing to do is to not allow you to proceed until you handle it.