In the end, being "kind of amusing" isn't enough to make a game good. Adventure games tend to immerse one in a world where stuff like, "The Nazis are going to take over the Earth using alien technology!" could be presented as plausible, or at least something besides the plot of a late night Sci-Fi Channel feature presentation. Nibiru doesn't quite live up to those lofty standards, unless you add a couple of guys in theater seats cracking jokes at the bottom of the screen. Nibiru just isn't worth it unless you're hard up for an adventure game and can tolerate the interface and slow-moving pace of the game, and you're willing to ignore as much of the foreshadowing as possible so you can be surprised by the plot twists.