MOOSE Points are similiar to Gamerscore on Xbox Live, except you probably won't reach over 1000 for a while.
You can calculate your MOOSE Points here.
MOOSE Points are calculated using the medals of my active games, those only being Rage and Mooseland.
They are arranged although not shown as
Easy - 5 Mpoints
Medium - 10 Mpoints
Hard - 15 Mpoints
VeryHard - 20 Mpoints.

You can also earn some medals based on the amount of points you have, although these medals won't count towards your MOOSE Point total.