Simple and boring.
The gameplay itself is very boring. There is no difficulty in this game. There is no challenge. Any map with only 2 gates can be beaten very easily. And the map with 3 gates is almost as easy. Going through this whole game until the last level without losing your multiplier is extremely easy.
The only "hard" level in this game is the last level, and it's so simple, actually losing on it is almost impossible, since you only lose lives for hitting a bomb.
There is very little fun to be had in this game. No power-ups, points mean nothing, and as I said, there is no possible way to lose. Each level is a repeat of itself.
Being able to play through the games as many times as you want without your points resetting makes the game way too easy as well. You can do horrible, but if you're willing to invest the time, it's all good. Which zaps more of the "skill" needed to play this out of the game.
The times for the last levels are horribly long. And many times, I'm waiting for it to just be over.
You've made improvements to the game, and for that, you get a point. But you didn't do anything for this game to be challenging. Such as a fast 3 gate level. That would be very difficult. But it doesn't exist. The last levels all involve a single gate. Which makes the last levels a joke.
The rank system is extremely bad. 500 balls per rank. Which only add a single multiplier. To obtain the top rank, you need to get 5,000 white balls, AND not miss the rank ball. That's 3 plays. You can obtain the top score medal in a single play though. What is the point of that?
I suggest lowering the amount of balls needed per rank or have the rank awarded to you directly. Something to make it fit somehow. Because if a top score medal can be earned in a single game, and a medal that helps improve your game can only be earned in at least 2 games, what is the point?
I'm not sure what you can do to improve this game, but it needs improvement. Add more balls that take a life from you. Such as one that if it passes a gate, takes a life, instead of kills you instantly. Maybe balls that are worth double the points, instead of a rare 500 point ball. Make it so you can't play an endless amount of times, because that cheapens the game's score system and the medals.
This game has very little replay due to the type of game it is, but it can be improved upon.
If you ever want to make a good game and give it medals, do so. But don't make a bad game and have people play it 4 times in a row to get a single medal. Especially when there is no difficulty or fun in the game and the medal order is broken. It's a slow painful grind where the only thing you have to do is beg a higher power for it to be over soon.