Here is the full list of all 18 BoneBone achievements.
Buy weapon with magic modificator!
Buy legendary weapon!
Save 10 refugee!
Buy 1 archer, 1 gunman, Tower level 3, Gun (player), Tower Gun, Crossbow
Buy tower level 3
Kill 15 skeletons in the first wave
Earn more than 5000 gold
Survive more than twenty waves
Buy Gun for player
Buy 5 archers
Buy Crossbow
Buy 20 arrows for bow
Buy 1000 hp for wall
Kill 100 skeletons in one session of the game
Survive more than five waves
Hit at least once
The first time in a game