Here is the full list of all 29 Sneaky Sneaky achievements.
Sneak Kill 3 enemies while they are eating bait in a single level.
Sneak Attack a sleeping enemy.
Buy every shop item at least once.
Feed a skeleton some bait.
Anger a Ham Troll into destroying 3 or more objects.
Kill 2 enemies at once with a bomb explosion.
Lead an enemy to 3 consecutive search points by breaking jars.
Consume 10 health potions.
Stay on 30 sand tiles with an enemy present.
Kill a Burrowing Skeleton with a bomb while its above ground.
Complete the main campaign.
Finish a level without killing any enemies.
Fully level up your stats.
Collect every ruby.
Awarded for completing the City zone.
Have 5000 Gold in your wallet.
Kill an Archer with your bow and arrow.
Awarded for completing the Canyon zone.
Kill an enemy with a spike trap and switch.
Survive an encounter after being detected 3 or more times.
Land a Long Shot with the bow.
Sneak Kill an enemy distracted by a jar.
Sneak Kill an enemy who is searching for you.
Awarded for completing the Forest zone.
Destroy or Harvest 100 tiles. (Trees, Rocks, Barrels etc.)
Successfully land 5 'Sneak Kills' from a bush or hay in a single level.
Finish a level without being detected. (Excludes tutorial level)
Execute 5 consecutive Sneak Kills in a single level.
Collect your first ruby.