Thank you for instructions. I'll go slower. I think i pushed in slow but too high increments.
There are two progression bars. One, the far left one is the pain bar and the other next to it (the one with the heart is the pleasure one).
The logic is simple. Just as you would perform anal intercourse with your partner, I imagine that you don't plunge your cock all the way as soon as you get in, you will have to do it slowly. Very slowly, just as the instructions are directing you to do so. You give her pleasure and get the heart bar filled while you are making sure that there is minimum pain. Remember, it is anal intercourse and the pain is supposed to exist but the pleasure is stronger. Good luck!
P.S.: In case you don't succeed, I have posted my save here:
https://f95zone.to/threads/my-cute-roommate-2-v1-1-05280-extra-astaros3d.90002/post-13993942
Which is exactly after the minigame. Enjoy.