The later stages are really - grumble grumble

I've already reached stage 199, and everything was smooth sailing until then. From stage 170 onwards, there are a few stages with tons of bombs, and I keep hitting them, forcing me to watch ads. Then, at stage 199, usually when you can't finish a game, you can watch an ad to extend the game time by 10 seconds. I already felt like the game's fluidity was a big problem with this mechanic. In this particular stage, it directly asks you to spend 800 points to extend the time. The points given during the game are usually not enough, and then you have to buy them with real money.