Create the Alien Game prototype within 7 days.

My family and I have been playing a game called Burglin' Gnomes.
We enjoyed the game but we didn't like the aesthetics and the overall feel so we decided that we could try and make our own game but with Aliens instead of Gnomes and change the objective of the unpolished reference game.
So with the magic of AI, tools like Blender and some other generative software we will create a prototype that we can play within 7 days (or as quick as possible) to see if this project is worth more of our time and effort!

In short the current plan looks the following:

• List the main gameplay from the reference game
• Start a project in Unity (or any other Game Engine that is reliable)
• Create the gameplay only, no graphics or models. Only Blocks or primitive shapes. (describe the gameplay detailed to AI so it can write the scripts)

Rely on AI and other generative software for quick results. It's a prototype not a finished product.

• Imagine the graphics and models. What should the game feel like? Understand what feeling and aesthetic we are looking for.
• Create Art for inspiration or find art for inspiration and future guidance.
• Create primitive or simplified graphics and models.
• Implement Multiplayer for testing.

The final result of these 7 days should be a game we can play either together or Singleplayer. As long as it is enough for us to evaluate the time and effort needed to polish and finish the game.