Play Onslaught 2 here, one of the best flash games ever made! The bad guys are coming after your base!! They are doing their best to get into Area 51 (The name of your base) and you have to build towers to prevent the bad guys from getting there. Every bad guy that you kill, you get an amount of money depending on what wave number you are on. When you get this money, you can use it to build new towers or upgrade your existing towers to gain additional powers and enhancements. The Modifier Turrets These turrets have no direct firepower themselves. They only increase the abilities of other turrets to give them extra damage, speed, or range. You need to strategically place them to win.