Alarm! A portal has opened with sticky monsters through! As the Lead engineer of the space station you have to use all possible defences to exterminate them. Develop your strategy to wisely place traps and turrets along the maze. Portals are where invaders spawning, so it will be wise to start your monster attack right at the stop. Use all sorts of upgrades to successfully fight back enemy waves. Such defense games online are naturally regarded as free arcade games for boys. However their comics art and vivid soundtrack might also appeal to all kids.