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