Sniper Elite: Resistance

This demands completion of all the Optional objectives Sniper Elite: Resistance has to offer, so be sure to hit all of the bases during each mission. Some objectives won't appear unless you've dug up the necessary intel, found as Classified Files or looted from certain Nazi Officers (usually the ones dressed in black with their fancy caps).

Each mission usually has a kill list target or some form of sabotage to execute, so make sure you've completed everything before you exfiltrate. You can always use mission select to go back and polish off any objectives you might have missed – just make sure to finish the mission once you've finished any leftover objectives, or they won't register as completed.