Indeed, when changing the "Wait for Vertical Refresh" parameter in the video card settings from "Off, unless applications specifies" to "Always On", the bug disappears.But why didn't the bug appear at a lower resolution...
I assume on a lower resolution the game has less work to do so it's more likely to hit the correct spot by accident. I think from now on I will be enabling vsync in my games by default. But I'm not going to update KNG during the jam, obviously.
