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