I know change in general can be immediately off-putting just by virtue of it being a change, but, Adventure Time as a 3D animation is... D:
Maybe it's the loss of exaggerated eyeball motions and facial expressions, or the pronounced boyishness in Finn. Whatever it is, this rendition of season 2's episode, "Go With Me," by YouTuber Mike Inel is well-done and weird as shit. Mike is planning on turning it into an Oculus Rift-supported "game" (his quotes) at some point in the future, too. So maybe it will be even weirder yet.
Here's a comparison to the original, as well as first-person perspective views from Marceline and Finn, which I imagine is what will be incorporated into the "game" mentioned earlier.