Omega Crisis

You have been tasked with the defense of your system and they have given you a gigantic laser cannon as well as some remote turrets to play with. Unfortunately the systems that you're defending seem to be very popular with the invading aliens.

Pretty much everything in the game is upgradable. You get access to the upgrade screen at the beginning of each level. Remember to use your research points wisely as the bigger aliens are really tough.

Mouse.

Remember to add more cannons to your defense as more gain more resources.