This apparently has been patched...***NOTE***:
According to Blame Essence:
Never mind. Reinstalling the game on your main or a second phone fixes it. Simply finish the first mission and as soon as you die and sign in, the game will start to randomly unlock all achievements except for Rocket Scientist.
However this is somewhat misleading as when I did this some
of the achievements unlocked but not all of them. You've been warned!.
So there's an easy way to get this early on when you play.
When you complete 3 objectives your multiplier goes up one.
Now, I could be wrong on this so let me know.
If you close out the game when your multiplier moves up, when you re-open the game it will automatically level your multiplier up again after you finish your run. I guess it doesn't fully recognize that when it happens.
This caps at x20, however you won't unlock:
Anyway, when you get to 20x, use a +5 boost at the beginning of the run to take you to 25x, and hope you stumble across a x2 power somewhere in that run to get you to 50x.
Achievement will pop when it happens.