If you don't enjoy this game, it probably makes no sense to continue punishing yourself. Sometimes we must do what we must in order to attain a worthwhile goal. We study, we invest, we do all these things what are hard but will benefit us in the future. Completing one's games collection is not a real benefit, it's an arbitrary goal. Think about it, if in the past you didn't add that game to your collection, this issue wouldn't have arisen. It feels good to complete stuff, that's our reptilian brain talking. Watching a number go up is oh so pleasant. But you are probably better off not following your instincts on that one. Completionism is such a fundamental thing that it's being taken advantage of over and over in games. It's forcing us to spend time doing something we dislike for a few molecules of dopamine in the end. And then we regret it. This is different from playing a challenging game that you have to practice to finish. In this case it's best to just quit.