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