X-Men: Destiny

The difficulty achievements stack in this game. You only need to play the last level on the hardest setting. You can play through on just mission 8 to save yourself time. If youre having trouble beating Bastian, check out the guides for the Omega Level Mutant achievement.

This is pretty self explanitory, except for one nice little shortcut: the difficulties stack. If you beat it on 'X-Man', you also get the achievement for beating on 'New Mutant' and so on... so if you decide to go straight for X-treme on the first playthrough, you can get all 3 difficulty related achievements in one go. However, if you're going for 1,000 points, you'll have to do multiple plays anyway, so might as well start off on a lower one to get the hang of things.