River City Girls 2

For this achievement you have to find and complete a event which is located in the maze in Flatirons. Go to Flatirons Witchy Woods entrance and follow this path:

• East
• East
• Northwest
• North

and you should end in the correct area with a skull on a branch in the middle. Interact with this skull and complete this event (Kill some waves of enemies, nothing special). After you complete the event the achievement unlocks.
In the same area is another achievement (visit the store in this area)

From the Witchy Woods entrance, head east twice. You should be in a room with a pan on a stump in the mud. Head northwest then climb up the vines and go North. You should be in a room with bear paw prints on the ground and a skull/totem in the centre you can interact with. Once you do, you'll be locked on the screen and must defeat a few waves of enemies. The achievement will pop once you defeat said enemies.