This achievement requires you to find all of the chronon particles and then unlock every upgrade. If you missed a chronon particle, you can always replay the section. You don't have to complete the entire section. Once you find it, you can immediately quit to the main menu and choose another section to (re)play.
There was a brief delay between when I unlocked the last time power and when the achievement unlocked (I think it didn't unlock until I hit the next check point) so if it doesn't unlock for you immediately, keep playing and it should.