Human Alien Battle games

Human Alien Battle is a tower defense game that pits the human army against the monster army. You are the commanding leader of the human army and you are expected to bring into use all your experience and strategy making abilities.
The human base is about to be attacked by the monster army and you being the leader of your side will need to deploy trained troops in tactical positions to counter attack the invading monsters.
Remember that the monster will keep getting dangerous wave after wave and the only way that your troops can match up with them is by getting upgraded. So as you play the game Human Vs Monster, you not only need to deploy troops but you will also need to upgrade them on every given opportunity.