Here is the full list of all 11 Reagan Gorbachev achievements.
Complete the game. (32 levels)
Kill 20 or more enemies on any level.
Destroy all the fuel in the fuel depot. (Level 21)
Discover a secret room.
Answer 20 trivia questions correctly.
Answer 10 trivia questions correctly.
Answer 3 trivia questions correctly.
Complete any level without setting off any alarms.
Complete a level.
Finish a level without killing any enemies.
Complete any level in less than 20 seconds.