An update on this hack: Honestly, neither of us have really worked on this in months. We still won't say it's cancelled, but if we have no ideas, or just don't feel like working on it, we won't. We both don't want to force ourselves to design levels. Because if we do, the levels won't be very good. And trust me, we both want this to be a great hack, with great levels and equally as good missions. I'm not sure what is going to happen in the future, but hopefully we will get back to this. Just wanted to update anyone who still cared, instead of leaving you in the dark.
Here is an image of the last thing I worked on a few months ago. This level was actually finished, minus texturing. (As you can see in the image.)

Working on Super Mario: Blast Off! With user BigBoo32.
Latest Preview:
https://www.youtube.com/watch?v=8jFXTQcHPb8&feature=youtu.be