I've played in the snow, speedball and woods. It's all fun. One time, we were at this field where it had snowed and they ran all the snow over with a couple ATV's so it all smoothed out, it was like playing on an ice skating rink, very fun, mad slides. Of course once upon a time when I owned a Model 98 FX and used Co2, I had just bought a Dye stainless and was using when it was 18*F with about a foot of snow on the ground. All you could see was snow and pink goo coming out the end of my barrel, not good.
Here's some pictures of a speedball game on ice (this is when they smoothed the snow out)
http://www.dougbob.com/washington/Buba's_Ranch.html