To me it looks very compelling, like the designer captured something quite extraordinary in terms of creating an emotionally compelling world where it feels those creatures are alive and real.. I'm glad to hear the reviews are more positive than it seemed at first.

Do I have to connect each laptop to the KVM switch via both a USB and a HDMI cable? That's alot of cables!

I haven't used a KVM for a long time but:

Quick answer is yes.. All computers need to connect to the KVM with at least two cables, a video cable and at least one usb cable.  And then the KVM has a video cable connecting to your monitor and at least one usb cable connecting the mouse and keyboard, and possiblyo other usb devices like webcam.

I'm not sure how well webcam will be switchable, but it sounds like maybe youd need a (powered) hub for all your usb devices (keyboard, mouse, webcam) and just be connecting that to the KVM and switching which pc the hub connects to.

Some KVMs use their own software, I think many do not.  Some work better than others.  One way in which they differ is the maximum resolution supported -- so make sure the KVM you get can handle your max display resolutions.

I hope everyone is having a nice holiday season -- christmas if you celebrate it, and all the other holidays at this time of the year.
Stay warm and safe.