Well, except for the clan OmniMechs.
Many of the features seem to be ripped from the table top, at least at first glance. The mech design and slot system seems to exactly like that used by table top system, although the hit points and heat are a bit different (I think heat is multiplied by 3, and the hit points by 8 or something).
The initiative system is different, as are the perks, but the one thing I didn’t like was how you can’t run and shoot at the same time. In the table top, you can run (move 50% faster) at the cost of heat and attack penalty. This change has meant that jump jets are much more effective, since you can jump and shot at the same time.