Mini Cave Defense - strategy game

Mini Cave Defense is a free online flash game of the category strategy games.

Protect the human base from waves of hungry, pissed-off monsters.

Everything is controlled by left-mouse-click.
Select towers with left mouse.
Place towers on the floor and ceiling of the cave with left mouse.
Left mouse the "upgrade" and "sell" buttons then select a tower to upgrade and sell towers.
Left mouse "Start Wave" to start a wave.

A context menu should be shown when right-clicking or, on touch devices, long-pressing in the game. This menu especially allows to play in full screen and control the volume.