During the game:Light Blue - Ice; glides faster over.
Dark Blue - Water; if you hit this you go back to where you shot from. (unless you've changed setting)
Yellow - Clay; stops the ball.
Orange - Bounce.
Brown - Mud; dark/light version, darker one is harder to shoot through.
Dotted Blue - Water; spawns you like ordinary but you can go over this.
Dotted Red - Blocks which disappear when hit.
Dotted Yellow (?) - I think this one spawns you back at the START of the level.
T shapes - Warps you to the same color T on the map, one way.
(There may be other ones but I can't think of them right now)
You need to sign up to playforia.net, add your opponent (click your profile at top and change URL to their name and add). Go to multiplayer, chose your game settings and create the game for them to join. If you are still stuck ask and I will help.
Good luck everyone.