World of Van Helsing: Deathtrap

To unlock access to Scenarios and Endless mode, you will first need to complete all 13 story maps on Tier 1. They are completed even if you only earn 1 star (easy).

Once you have unlocked Scenarios, you must complete a Scenario on all 13 story maps. Before I hit level 100, I always chose less effective potions (bottom row, center). I believe you can simply chose level 1 for that and still get credit if you earn a single star, I always chose level 3 for that though (3 stars). A few maps I did, my base got hurt and I only received 2 stars and I still got the achievement. If you are already level 100 when you attempt these, I suggest you use "Gain 45% less Mana/Rage/Focus" (Very center of the 9 options). No need for exp boost once you max level, the item find will be more useful.

The maps don't seem to show you which have been completed like Endless mode, so make sure you keep track yourself which ones you did. Select a map to start (I suggest doing them in order, 1-13), then press Right Trigger to select Scenario. Then simply chose which penalties to use (each penalty increases difficulty and rewards).

*** I tried Scenarios at lower level with weak traps and had a hard time, these will be much easier to solo after completing all 4 tiers in campaign because of the high level traps. Easiest way to level is Endless mode (level 4, Bottomless Pit) in my opinion. Farm Scenarios or Endless mode once maxed for level 100 gear. 2 person co-op is the easiest, game gets much harder once you have 3 people in the game ***

Finish the 13th Scenario and your achievement will pop.

*** UPDATE *** It sounds like new scenarios have been added for this game, and some people are having trouble unlocking this achievement when completing the original 13. If you too are having trouble with this unlocking, try completing the first 2 newly added scenarios as well to get this to pop (see comments).

Congratulations