I'm always too late on this I guess. I made a 3D Dot Game Heroes tile set after I saw a screenshot some months ago. Now I make a higher resolution version, but I'm still not the first. At least I can safely say that I took the colors and patterns (where I could find similar terrain at least) straight from screenshots of the game that I made. I didn't bother with water or lava, because I could never get it to work right in the past and the water in 3D Dot Game Heroes is super shiny and not pixel anyway.
I'm making a 128x128 tile super HD version to have the boarder for each tile appear correctly.
The snowfall particles are in the root of the minecraft.jar and it's called snow.png <3
Tested it a bit. I tried enlarging the texture size to let me use smaller pixel. Ended up getting rid of the snowflake patterns. It ends up looking like a bit more realistic I guess. Still have no idea what kind of pattern to use if any.