I went into this design process with a completely different concept than what I ended up with. While I still wanted it to be a 2D platformer,  it was originally planned to take place in a tower (with heavy inspiration from the Dead Cells Ramparts level towers). And instead of zombies, the enemies were vampires. But while starting to translate that idea into Unity, I really wasn't happy with the results I was getting. So, I scratched that idea and interpreted my mad libs in a slightly different way. That's how I got the idea of caves. 

When I began to develop this further, I started having a lot of fun. I found some really great tile palettes and Unity assets and had a field day. The tilemaps were the most enjoyable part. It felt like I was painting each level. Since each tile is so simple, I felt like I had a lot of freedom on how to format obstacles and platforms. Very cool stuff! 

Here are some screenshots from my development as well as my full levels - - - 

Tile Palette

Files & Animator

Hierarchy:

Level 1:

Level 2: