Here is a 5 x 5 x 5 cube filled with numbers.
It's a 3D adaption of standard slitherlink puzzles.
You must create a solid 3D object such that the number in each sub-cube matches the number of adjacent faces.
You can assume that the surface will never touch itself except at connections.
It might very well be possible to remove some numbers and still have a valid solution, but since this is a new puzzle type (as far as I know) I'll give all the information.
Please let me know what you think and most importantly, have fun!