- Estimated Achievement Difficulty: 9/10
- Offline: 12 
- Online: 0 
- Approximate amount of time to 200G: 2-4 Hours [depends heavily on skill level]
- Minimum number of playthroughs needed: 1
- Does difficuly affect achievements: No
- Number of missable achievements: None
- Unobtainanle/glitched achievements: None
- Extra equipment needed?: No
This game is a very difficult 200. Most likely one of the most difficult arcade titles. The amount of time needed to complete the game depends almost entirely on your own skill level. It's possible to earn every achievement in one simple game session but it's at the very least, unlikely.
Welcome to Geometry Wars Retro Evolved! This game has a total of 12 achievements and it might take a long time to get them all. There are no known cheat codes for this game.
Step #1: Preparation
Most of the achievements for this game come from your overall score displayed in the top left corner. There are achievements for earning 100,000, 250,000, 500,000, and 1,000,000 points. That's the basic idea of "game progression" as this game has no actual levels. There are also achievements for surviving to each of those scores which means getting to that score without dying. These and the one for earning a 10x score multiplier will take the longest to achieve. Also remember that achievements will not unlock until the end of the game.
Step #2: Playing the Game
If you are trying to earn all 12 achievements in one game, you will have to start with "Pacifist". If you shoot, you'll lose the achievements and you'll have to play a second time or start over. If you earn "Pacifist" first, the next achievement you'll unlock is "Score 100,000". If you managed to survive on your first life that long, you'll also earn "Survived 100,000".
This progression is the same for the rest of the score achievements in their respectable order.
The next achievements are earned at different times. "Mad Cat Skills" will be earned once you reach 450,000 points if you can survive that long. Though dying will not forfeit your changes of earning the achievement. You just need to have 9 lives available to you in one game.
"Quartermaster" can be unlocked at 600,000 points but only if you use no bombs by that time. Using a bomb will not forfeit your chances of earning the achievement in a game. You just need to have 9 bombs available to you in one game.
As the guide says, the "10x Multiplier" achievement is awarded after killing 2000 enemies. This will take longer if you use a lot of bombs as any enemies killed by bombs will not count toward your score or your multiplier. So use those bombs wisely!
If you managed to earn all 12 achievements in one single playthrough... you're a Geometry Wars God. If not, don't worry. Keep practicing and you'll earn them all. Eventually. Good luck!
[XBA would like to thank Skillet for this Road Map]