Skin of Your Teeth award on 6 different levels(maps).
This can be done on at least Medium difficulty. Earning this achievement unlocks the Skulltacular! Crystal Skin.
- In levels with more than one crystal, only one of the crystals needs to go under 100 Eternia Crystal Health Points.
- The award 'Skin of Your Teeth' can not be achieved until after the first wave.
- The 'Skin of Your Teeth' award will not count toward the 'Daredevil' achievement if the level is not won.
- On Insane difficulty the core doesn't heal. Each wave completed with the core damaged to 100, after the first wave, award Skin of Your Teeth even if the core took no damage in that same wave. It is possible to get both Flawless Victory and Skin of Your Teeth since they both begin on wave two by having the core taken down to 100 on the first wave, with no further hits.