I assume you mean MVDK as in the series rather than just the first game. In terms of graphics, I've been looking for Tipping Stars / Miniland Mayhem tilesets for a fangame Unity project I was going to be working on. Couldn't find any, so I plan to work on replicating them as best I can. If I finish them then I might even release them on these forums (baring in mind, I'm not necessarily sticking to the SMBX aesthetic).
Example of what I have made so far:
These are obviously not perfect replicas (I'm not necessarily planning to make 1:1 copies of every single asset from the game) but I like how they've turned out. (Except the springs. I hate making springs.)