Going to try this during Social Saturday today, but a few thoughts just from looking around in it:
1) Lighting is a little bit dark. Everything looks grey instead of white.
2) The "blizzard" below just kind of looks bad to me, plus it hurts the framerate. It's cool that you're trying something unique, but I think I'd just remove it.
3) Since you're altering the map geometry anyway, I'd make it so it's easier for new players and don't require trick jumps to get to the flag.
4) The snow layers on some of the textures look kind of low res compared to the originals. Also, it might be nice to have the snow settling on the parts of the barrel that stick out rather than evenly scattered. There's also a seam where some of the textures don't tile well, but that's kind of minor.