MineCart Asset for Underground area

We don't need levers to work to use this, just think of them as either
another smashable or an object to jump on to reach new heights. Also,
It's not finished. I'm trying to flood as many art sources as possible.
I can work on polishing them up (changing, line width and style) later.
Also, I'm working smarter (using lots of layers) so clean up and polish
will be quick.