It’s advertisement spam. You will see that to play every level, you need to get one of the armor options by watching an ad. If you don’t, you will die very quickly. And you also have to watch ads at the end of each level. In the 15 minutes I played, I may have watched more ads than I would watch spending a whole day on YouTube. This all could be justifiable if the game had something to offer. You will be shooting in the same three stage designs, facing the same old enemies. There is a shop for you to buy guns, and you would think that they would give a short description about each gun, so at least you have a good reason to go through this mind-numbing game and feel somewhat powerful. No, it is too much work for them. Don’t waste your time playing this. It’s utter garbage.