If you need help making multiplayer, I can give some suggestions.
In this we would make a car game.
1. Make multiple cloud variables (xposition,yposition, and direction for one player, and same for the other)
2. Make these variables change when you use the arrow keys.
3. Set the xposition,yposition, and direction to the responding variable.
4. Make it so if one username is the same then don't let one player move two sprites.
This is all the help I can give. Tell me if I'm wrong.

I think it may be easier with 1.4 mesh

I doubt it, because the blocks and everything are already here. We just need to wait for cloud lists and strings.