In the "Rotwick" chapter, select every channel on the ground until the ninja master shows himself.
Easy "Great Defender" achievement
All levels until "The Dark Tower" must be completed under the normal or higher difficulty setting. Completing the levels under the casual difficulty setting will not qualify.
Easy "Heroic Defender" achievement
Complete all heroic levels under the normal or higher difficulty setting.
Easy "Iron Defender" achievement
Complete all the iron stages of the original levels (not the levels unlocked later), under the normal or higher difficulty setting. These are from level 1 to the Dark Tower. The Castle Blackburn, Fungal Forest, and all other levels that appear after completing the Dark Tower are not required.
Easy "Nessie" achievement
Select the bubbles in water in the "Nightfang Swale" map.
Easy "Nevermore" achievement
In the "Ancient Hecropolis" chapter, the crow can be found on the gravestone on the right side.
Easy "Still counts as one" achievement
Play level 5, "Silveroak Forest" in Campaign mode a few times. Each time, repair the Elves' Hut and recruit four Elves. Do not place any towers on the route to the Elves to allow them do as much damage as possible. Have your towers fully upgraded and place them just beyond the Elves to hit any enemies that get past. Note: It may be possible that melee damage is required to qualify.
