The original Defense Grid became quite the indie hit thanks to its pitch-perfect execution of tower defense gameplay and sharp writing. Not content to sit back and do the same thing again, Defense Grid developers Hidden Path Entertainment have cooked up a few new twists on this well-worn genre.

As you can see in the trailer above, Defense Grid 2 will offer two unique additions to the original game's build-and-defend style. First is the addition of AI partners. Though the game labels them as artificial intelligences, they really seem to be labels for special powers you can use to influence the battlefield, like an all-powerful satellite laser or a buff that causes your towers to Hulk out with power.

Also new to the genre is the ability to manipulate the battlefield on a larger scale, moving around potential defense points once you've got a feel for the areas that need defending the most. This helps combat the occasional rigidity found in many tower defense games, plus it just looks like fun.

Defense Grid 2 arrives for PC, Xbox One and PlayStation 4 on Sept. 23.