It all started when the game wouldn't save its progress to the Steam cloud, then I installed the game in another OS and I started from scratch because I forgot I had some local progress. Now that I started my old game I got a conflict:
https://postimg.org/image/6x1vd5e3p/

Obviously, I had no idea what to do without proper information about that save. I closed the window and I hoped Steam won't ruin anything. When I started the game again, I got this:
https://postimg.org/image/nyupf8syt/

Cool! But I don't remember how I assigned the upgrade points in my old game, so a better comparison would be useful. I can play around with the backup but that's not so cool.

So here's what I want to know:
1. Why not move a conflicting cloud save to an empty slot when you have one?
2. Why not be prompted to overwrite any existing slot? (by showing them all, and choose one)
3. Why not add a Cancel button on that window, so you can have some peace of mind that Steam won't bork your saves if you simply close the game's window?
4. Why not be able to postpone the answer to that question and be allowed to continue to the 3 slots, so you can at least check your existing slot and decide if you still want it?
5. Why wouldn't we have the option to move a save from a slot to another one, so we can avoid this kind of headaches? :P

Ultimately, what I really want is to make an informed decision on using the cloud save. Adding it in an empty slot is impossible currently, but I hope that will be a feature sometime soon. I'll just ignore the game until then because my local save is obviously more advanced. But I remember that my cloud save pursued the character upgrades that would help with my strategy, so my decision is split between the two. And they easiest way not to care about the differences would be to be able to move the cloud save in an empty slot.

Oh well, here's for hope!