They didn't cut that much from the ending but they short the hell out of it that's for sure, making it confusing. Like the explanation of how our MC is actually the game version, not the real one. He just got switched with the real MC when they were younger. So now they got switched back to their original places. It explains better in the novel than in the manhwa. It's also the same case with the relationship between the MC and ML, they show many cute scenes and shows that the ML starts to learn to trust others and rely on the MC and others.
I don't remember which link I've read the novel from but this was one of that I could find.
https://www.scribd.com/document/771768928/Creating-Hidden-Endings

It sad to see it ended just like that cause the story is actually good. The novel really captivated me and I rarely read novels. Only two or three like that. I was really excited about it getting a manhwa but at last.. it was rushed. Many things were cut from the novel and they didn't actually explain the plot much. And obviously the ending was rushed, making it unsatisfied and confusing.
I wish they would've continue it a little more, just a few more chapters. Overall.. could've been better but just read the novel.