Even the multiplayer works fine. I hosted the Multiserver on my Windows XP machine and connected as usual, without any issues. The Multiserver itself does not work completely though, so it still needs to be hosted on a Windows XP machine. When I connected two LF2s running on the same machine (maybe that was the issue, I think I didn't test starting them on different machines) the Multiserver noted their connection attempts, but didn't signal them to start once the required number of players has been reached.
As if that's not enough, even the FPSC works on Linux and when I tried it had immediate effect on LF2, which could be coincidence. However, if it's not coincidence, it works even better than on Windows.
What I didn't test so far is, to maximize the LF2 window. I guess you could simply set an emulated desktop in Wine with a specific size and then maximize the game to the extend of this emulated desktop. Or maybe one could make the Unity launcher disappear automatically and then maximize the game.
Too bad Little Fighter 2 didn't run that well under Wine earlier. At least I don't have to fear the next Windows releases anymore and maybe some Linux games will give it a try.