Coming... is a simple yet addictive shooter inspired by the old classics such as asteroids and space invaders. The game needs some balancing but considering it is free and the developer is promising a bunch of updates in the next versions there should be plenty to look forward to. I suppose in-app purchases have allowed developers to take the development one step at a time adding (and charging) for additional features over time. This is one of those examples but whether the developer will charge for additional features remains to be seen. Best to think of it for the time being as a first iteration of something that could be great but for now, enjoy (for free) this simple, clean and quite addictive gameplay.