Thanks to GM for these, here are the Mass Effect 2 Achievements.
| Achievement | How to unlock |
| A House Divided (10) | Hack a geth collective |
| Against All Odds (15) | Survive suicide mission |
| Agent (50) | Complete 5 missions discovered by scanning unexplored worlds |
| Battlemaster (10) | Gain the loyalty of the krogan |
| Big Game Hunter (10) | Thresher Maw defeated |
| Brawler (10) | Shoot and kill 20 enemies while they're knocked back by a punch |
| Cat's in the Cradle (10) | Gain the loyalty of the Assassin |
| Catharsis (10) | Gain the loyalty of the biotic Convict |
| Colony Defense (25) | Defend a human colony from attack |
| Doppelganger (10) | Help the Justicar resolve her mission |
| Explorer (10) | Visit 100% of the planets in an unexplored cluster |
| Fade Away (10) | Gain the loyalty of Archangel |
| Fashionista (5) | Personalize your armor in your quarters on the Normandy |
| Friend or Foe (10) | Obtain geth technology |
| Ghost of the Father (10) | Gain the loyalty of the Cerberus Operative |
| Ghost Ship (25) | Complete the investigation of a derelict alien vessel |
| Head Hunter (10) | Perform 30 headshot kills with any weapon on humanoid targets |
| Highly Trained (15) | View all advanced combat training videos at Shepard's private terminal. |
| Incineration Specialist (15) | Incinerate the armor of 25 enemies |
| Insanity (75) | Complete the game on the "Insanity" difficulty level without changing the setting |
| Long Service Medal (75) | Complete Mass Effect 2 twice, or complete it once with a character imported from Mass Effect 1 |
| Master at Arms (15) | Kill enemies with 5 different heavy weapons during the game |
| Merciless (10) | Make 20 enemies scream as they fall or are set on fire |
| Missing in Action (5) | Save your crew from an overwhelming attack |
| Mission Accomplished (125) | Save humanity throughout the galaxy from certain annihilation |
| No One Left Behind (75) | Keep your team alive through the suicide mission |
| Operative (15) | Complete a mission discovered by scanning an unexplored world |
| Overload Specialist (15) | Disrupt the shields of 25 enemies |
| Paramour (50) | Successfully pursue a relationship with a teammate |
| Power Full (15) | Evolve any power |
| Power Gamer (10) | Reach Level 30 with one character |
| Prospector (5) | Retrieve mineral resources by scanning and probing a planet in the galaxy map |
| Scholar (15) | Unlock 15 new Mass Effect 2 codex entries |
| Scientist (10) | Complete any research project in the Normandy's laboratory |
| Suicide Mission (50) | Use the Omega 4 Relay |
| Tactician (10) | Hit 20 different targets with multiple biotic powers to combine the effects |
| Technician (15) | Obtain 10 technology upgrades |
| The Archangel (10) | Successfully recruit Archangel |
| The Assassin (10) | Successfully recruit the Assassin |
| The Convict (10) | Successfully recruit the biotic Convict |
| The Cure (10) | Gain the loyalty of the Professor |
| The Justicar (10) | Successfully recruit the Justicar |
| The Krogan (10) | Successfully recruit the krogan |
| The Prodigal (10) | Gain the loyalty of the Cerberus Officer |
| The Professor (10) | Successfully recruit the Professor |
| The Quarian (10) | Successfully recruit the quarian |
| Treason (10) | Gain the loyalty of the quarian |
| Very Elusive (10) | Return to active duty |
| Warp Specialist (15) | Warp the barriers of 25 enemies |
| Weapon Specialist (15) | Fully upgrade a weapon |