How should I design/make it first-last?

[Composer_Dev (Dragons_Tea)]

Hi, am back this is about my another post I made about my game.
I was wounding what is the best to get started on this like what part should I work on first?
Building it?
Scripting it?
Work on the story more?
Or plan out how the game will work?

My game idea (Of Beats and Shapes)

Hello, people of Dev Forum I have a game idea and tell me what should I add or remove or need more detail. So the game will be called Blox and Sounds it’s based off of beats and shapes. What is Beats and shapes? is a chaotic co-op musical based on three simple things: avoid Shapes , move to the rad Beats , and die, repeatedly. What my game is about: You start out as teen named Max or if you are a girl your name will be Zilly. Intro You start out with talking to your mom about you joining t…

[watermelonroach]

The way that it would make sense to me is to:
1st: Plan out how the game will work (gameplay mechanics; how do boss levels work, etc.)
2nd: Work on the story more
3rd: Build it
4th: Script it

[teslobo]

1. Plan the core mechanics

2. Script a minimum viable product (i.e the least work possible to make the core mechanics useable) so you can test and iterate on your mechanics. Mario’s movement was famously worked on for months before they started building anything else, and you should do the same with the most important part of your game.

3. Build your assets and gameworld. Keep testing to make sure your mechanics and world work together.

4. Script any subsystems you want to include that aren’t important to the core of your game, but is something you still want anyway. This includes pets, minigames etc.