If you want to acquire this achievement very easily, just play the mission on Amateur. When I got mine, I was getting the 18 Score Stars, so I got the points for each one destroyed in addition to killing all the (few) enemies and completing the mission in thirty-ish minutes.
Essentially the same principles apply to the Lost in Nightmares level as did to the main game. You'll still be rated for accuracy, kills, completion time, etc.
New this time around is the score stars, some of which are the shootable emblem style (also related to a separate achievement) and some that are pickup style. The latter can be found on fallen enemies, in crates/vases, and so forth.