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