Hunting Guardians is stamina-intensive. Save your specifically for Giant Guardian events rather than wasting them on low-level polar terrors.

Always choose over one thick layer. Enemies in Giant Guardians have "Overkill" damage. If a Giant Spider hits for 500 damage, hitting a 1,200 HP wall wastes 700 damage. But against two layers, the spider breaks the first wall, wastes damage on the second, and gives your Guardian time to kill it.

Reaching level 50 is the "end" of the tutorial. After that, the game introduces – mirror versions of your own units.

Before you hit "Start Battle," run through this checklist: