Not sure as never played mass effect...
Missions include, (all loosely tied to some sort of story. Very loosely)
Tower defence type mission with waves and after a certain amount you can vote to carry on or leave with prizes, or carry on to gain better higher prizes and cash.
Domination type games 4 locations vs alot of bot enemies
Stealth missions
General, kill bots and make it to the extraction point
Rescue important hostages
Kill/capture important targets, who once found will just run away really fast, you must capture them before they reach their extraction point
Then there's bosses at the end of each planets set of missions
I really recommend it to anyone looking for a new game, it is somewhat repetitive mission wise on occasion, but it has a lot of unlocks less and replay value...