While there are an awful lot While there are an awful lot of missable achievements in this game - and a difficulty trophy, to boot! - you shouldn’t let that scare you. Mass Effect 1 is actually a pretty easy game to 100%, with most of the missable trophies more being a matter of intentionally going out and grinding for them instead of some obscure thing you can honestly miss out on. If you go out of your way to complete every assignment and explore the galaxy, many of the semi-missable trophies (Archivist, Medal of Exploration I, Medal of Exploration II, Medal of Exploration III, Principled, Colonial Savior) should occur naturally. If you swap your squadmates out when you unlock their trophies, you should get all of those, too (Soldier Ally, Sentinel Ally, Krogan Ally, Turian Ally, Quarian Ally, Asari Ally).