Total-conversion mod for SWBF2 that adds the Mass Effect era to Instant Action. You can fight as the Systems Alliance, the Heretic Geth, the Collectors, or the Evolved Geth on six new custom maps, all of the stock maps, and all maps from the Sol Map Pack.

Venoda says

10/10 -

This mod is not only a complete dream for any Mass Effect and/or Battlefront fan, but the best modeled mod made for Battlefront II to date. Using stock models only as placeholders for upcoming features, the content is very fresh in the crop of BFII mods, most of which involve recolors and retextures of already existing in-game assets.

Edit as of R5 Prerelease (July 2014):

Mass Effect Unification continues to march it's way towards being the outright best mod for BFII to date. Unification's gameplay is unlike that of any other BFII map or modification with it's asymmetrical teams, player-seeking powers, intense sound-rich battles, and perfect replication of the Mass Effect feel. Unification has managed to combine my favorite RPG series with my favorite shooter making it my absolute favorite mod of all time.