It's something that improves with some regularity. In the past few weeks or so I've noticed a lot of improvement with this game.
The most obvious change is that I'm much better at it. I've beaten the game in the past week a few times. There's a level where you encounter bricks that take around ten hits to destroy. It's quite challenging, because when you hit a brick vs hit the wall, the ball bounces off at a random angle. That means that in order to hit the brick again, you have to adjust the paddle to hit the ball at a new angle so that you're able to hit it again... and again, and again.
Another thing that I'm noticing is that on some levels, the bricks come at you. When they come at you, it's pretty trippy. The feeling is very real, as though I could reach out and touch the bricks as they go past me.
The other thing that I notice is that I have much greater control of where I hit the ball. I'm becoming much more aware of both input streams. Diplopia is designed so that you need to use both eyes simultaneously in order to be successful at the game. But if you are stereoblind, and you suppress, then it's hard to hit the ball, period. Well, I've been able to hit the ball pretty easily for the past few months. Now I'm just starting to get good at aiming the ball, and adjusting the angle with which the ball bounces off of the paddle. The angle depends on where on the paddle the ball bounces from. So it seems that I've graduated from barely being able to play, to getting fairly proficient.
It's interesting, because the way that the game makes it so that you need to use both eyes is that the paddle is seen with the right eye and the ball is seen with the left eye. Well, now it seems that I'm pretty well aware of both simultaneously. I was always semi-aware, but now the awareness is just stronger, more robust. It's only going to get better too, I imagine.
So yeah, I'm happy. Things are moving in the right direction still. Just keep going. As Winston Churchill said "If you're in hell, keep going."