just create 15 different assets in blender export it to an (.fbx) file so it can be used in unity.

In every asset create: an examples, All the parts and their materials with textures(but just zip the actual textures); and zip the models and parts in one folder and textures in the other.

If you are able to pull this of then put it in a game engine and add it by the side of the work, if done, explain the game in summary of: app, story and controls.

Good Luck 🍀!!!

You're going to need it.

as a wise person says:

"Try Try Try, until you finish",

"You can do any thing",

"Ask for help(but don't download it!)",

"Just do it",

"Do anything you can then pray for help.".