So when reading many complaints people have against this manga, it's important to understand that all versions of Yume Nikki are different stories. The same dream worlds are contextualized completely differently between versions, resulting in very different subtext. Given both the games rely almost entirely on subtext to tell their stories, that alone should indicate that they are separate stories, even without them having wildly different endings.
More importantly than trying to convince you whether the manga is good or bad, I would like the take-away to be that it's not beholden to the original work other than its use of the basic setting and characters. The manga definitely stands out by having an explicit story rather than a largely implied one, but there's nothing particularly wrong with that. It's just a different decision for a different story.
