A common theme in the genre is one of unlimited ammunition, and limited special weapons if the game has them. (joystikrevolution.com)
* Cyclic rate is how fast a gun will fire with unlimited ammunition and an indestructible barrel. (businessinsider.com)
There is a slight amount of replay value as you unlock unlimited ammunition weaponry when you play through the game, but these are only available once you have completed the game. (darkstation.com)