Well, I just installed that game and it works fine for me.
That's my dmenu entry for it:
Icon = "res/games/alice.png"
Name = " beat2x"
Executable = "./beat2x"
WorkDir = "/usr/local/games/Beat2x/"
Be sure to check if you use the newest kernel/rootfs.
".ogg file is unrecognized music format" doesn't sound good..