Vampire Survivors - Open beta test for Online mode, with free roaming!

Your question mark key seems to be sticking.

The only part that makes it somewhat clear what the mode is is the part they explain the differences between local co-op and online mode.

This is a list of gameplay changes compared to a standard local co-op run:

They could have been a little more explicit and called it “online co-op mode” or something, and had a paragraph explaining what it is not just how it’s different to something else.