Just pay the initial fee, and you get everything. And for a price of 20 $, you got alot to play with. Different pilots, different vehicles and different weapons to put on those vehicles as well as a crapton of levels. With the amount of customization and approach, you will never run out of things to destroy. It also helps that the music greatly complements this game's atmosphere. Playing this reminds me of how video games are supposed to be. Pay once and you get a full experience. This game may look dated, but it offers far more content than your average AAA videogame as many of the things you can unlock here are not hidden behind microtransactions that would shoot up your purchase of a game into hundreds of dollars overall. So if you like destroying things with robots, tanks and hovercraft, this game is for you.
