MP is fun, and I was surprised by most of the polish. However the more I play it, the more I wish it was released later as its own thing. More game modes, more maps, and better story. If the reapers are all powerful and conquering, how does a ragtag band of aliens hope to make any progress? what are we fighting over? isn't every battle just a fighting retreat? that's no fun.
Multiplayer is nice addition to singleplayer, when played with friends, but only for few matches. I brought this game for SP so I would rather have expanded SP content DLCs than some MP ones.