The mice try and get the cheese while trying to avoid being pushed around by others.
Try to avoid getting shoved into the pits by other mice. Unless you're going for first place, it's a good idea to stay back and wait until most of the mice clear out.
There's not much a Shaman can do in Map 43 aside from plug the gaps, which they should begin to do immediately after the round starts. The shaman must be careful to not cover the cheese with a plank, as it would make the cheese unattainable.