Invaders from the deep

Invaders of the deep is an anti tower defence game meant as a new take of the tower defence genre. Where the player send creeps to destroy a human city using unspeakable terrors from the deep. The player does this by selecting creeps to send through a portal and attack towers and strongholds that an AI player builds. Upon completing a level the player gains a number of upgrade points, use these points to upgrade your creeps and become more effective against the difficult levels.