My personal opinion is that tower defense games have everything a true gamer needs to become addicted to a game. And Sentinel 2: Earth Defense is just another truly impressive game  that definitely fall into the addicting games category. Your efforts and sacrifices were not enough to keep the aliens from Sentinel 1 away from your planet. Now they have returned more cunning and eager to revenge.  So again, you have to defend your base from numerous waves of aliens as they traverse preset paths. Sentinel 2 has seven towers, and while some are genre standards, there are some creative towers like the ion tower, which creates a fire on the path that will burn oncoming aliens. You can earn money from defeating aliens, and you can use these money to buy stronger and more powerful towers, and upgrades for those towers. Keeping your intermediate gates intact adds to your score, and if your final barrier is broken through, you lose. In addition, after each round, gates beam up energy to the Sentinel. Energy is used for utilizing one of the Sentinel’s four weapons: homing missiles, attack drones, time warp, and orbital laser… all of which affect the whole map and are extremely powerful. This game contains two game modes: Campaign - where you have four maps with a preset number of waves, and you cannot unlock the next map, until you have completed the one you are on at the moment, and you also have to be aware that each map contains four levels of difficulty; and missions mode - where you have ten missions with tricky scenarios and very low resources, so you will have to defeat the aliens just by using your God given skills. If you download this game you will notice that the graphics are definitely one of the best, the theme is fantastic, bringing to you an impressive and highly detailed sci-fi world.