Can usb cross link be used for multiplayer?

Technical feasibility and practical feasibility are two different things. While using a USB transfer cable to play LAN games would be technically feasible, it certainly isn't currently practical. As far as I know, USB transfer cables make an internal drive on one computer look like an external drive to the other computer, and don't look like a network interface. Since these cables are only intended to open file handles, and not streams (sockets), they aren't a good choice for sharing data in real time. There's some trickery that you can do to make a file handle act like a stream (or conversely, make a stream look like a file or 2), but it seems to me that this could become tedious to set up.

The better choice would be to use Firewire, which has native support for network links, and is typically already recognized by the OS as a network adapter.

I've used a "Windows Cross Connect USB Cable" between my Linux Boxen many times. Windows machines are pretty much hard-coded to see it as a 'special device, needs fancy software'... whereas my linux boxes see it as a usb network cable.

Plug it in, I get /dev/usb0 (usb1/usb2/etc) to which I can assign an address with ifconfig, network manager, wicd, or whatever. it's a decent speed cable, just not long enough sometimes.

I played around with plugging BOTH ends into the same machine too... the chip inside offers the SAME MAC on both ends, so I get a complaint that you can't have two devices with same MAC. {Shrug} Nice to know how they did it.

Simple answer: It's just a usb network cable with a particular vendor/id which lets MS Windows identify it and force you into their "magic programs". Bleah. Using an OS which doesn't tell me what I can do, it's a very handy cable to transfer files and data between two machines next to each other. I suppose you could write/find a driver to snatch the usb device away from Windows before it invokes the "magic program"... Of course, YMMV.