ReactorX

The description is unclear. You have to power up 50 or more energy blocks on a single screen. The earliest this can be done is map B7. Clear map B7. Not only will this achievement pop but so will all the other 4 achievements in Title Update 2.

If you have a save file from a previous playthrough, go to level B7 directly and clear it. The achievement should unlock (if it does not, see below). If you are playing a new game, start from the beginning and play through level B7. All Title Update 2 achievements will unlock.

If you have a previous game and go to B7 and clear it, the achievement may not unlock. If so, you should delete your previous saved data from everywhere, uninstall the game, clear the cache, restart your XBox, reinstall the game, and play until you get to map B7. When you play map B7 all achievements in Title Update 2 will unlock one after the other.

Note: Your first step should be to go to level B7 and clear the map. If you have problems, take remedial action. You may not have to do all of the above. For Title Update 1, I found deleting the saved data was sufficient. For Title Update 2, I had to reinstall the game in addition to deleting the saved data. Rather than do fault isolation, it's better to bite the bullet and do all three things: Delete save data, uninstall the game, & clear the cache. After you do all these three things, reinstall the game and you should be good to go. You'll have to start the game from the beginning but it only takes a few minutes to get to screen B7.

To delete save data from everywhere: Highlight the game. Press . Choose to manage game and add-ons. Choose saved data. Select your GamerTag. Choose to delete saved data from everywhere.

To clear the cache: Press on the console (not the controller) and hold for ten seconds as the XBox turns off. Disconnect the power for 20 seconds. Reconnect the power and turn the console back on.