If you could create a game about anything, what would it be?

I don’t know what i’d call it but I guess I call it a transporter so you are delivering high performance cars to clients around the UK with story line that progresses as you complete missions ending up with you escaping the country at the end as the jobs get more and more sketchy. When you deliver a car sections of the cities where your delivering to open up until the whole city is open and post game the cities inn the game are open for free roam with side missions like races and the like.

That sounds like it could really be fun! Sounds like a lot of driving, so the driving mechanics would need to be top notch!

A game loosely based on the novel 1984 by George Orwell as well as the movie They Live could be somewhat interesting. MC lives in a dystopian society and begins to wake up to the evil going on around him. Then things get sci-fi and and the MC finds out the the so called 'elites' of the world are actually tyrannical entities trying to enslave humanity and keep their consciousness trapped in a never-ending loop of suffering.

Near the end of the game, the MC awakens the true power that lays dormant in all humans by unlocking aspects of his consciousness that he didn't know exists, thus eliminating this evil with said newfound power.

Gameplay will revolve around Uncharted-esque type movement and gunplay with crazy set-pieces sprinkled in between.

I'd design a stealth game based around roguelike mechanics in a dieselpunk style setting.

It's one of a few potential concepts I've had in mind for games, but I feel that it's the most viable.

Personally I don't know much about games, but my friends and I have an idea about private boarding school themed game
e.g. Avoid the head master, matron etc,
Deal with too hard potatoes and pink chicken in the dining hall
stop chemistry classroom from exploding

The life and times of Oz in Auf Wiedersehen, Pet

Sounds remarkably like Bully, released in 2006

The life and times of Oz in Auf Wiedersehen, Pet

Honestly wouldn't be surprised if that exists on a Spectrum cassette tape somewhere.

I'd create Super Mario Odyssey 2.

Railrider.
Think if an on-rails game was given vastly more choice and variety. At no point do you ever stop in this game unless you fail to navigate obstacles. It's not just QTEs. You're always moving, whether on your own feet, in the air, by boat/jetski or by vehicle. There is no end of chapter. The only way to pause is to exit the game which autosaves your progress.

You start off at the top of a mountain. You can either go down the zipline or the cable car. Often, the progression from one section to another will be unlikely / over the top in the arcade tradition. Sometimes it will be played for laughs, sometimes the game will try to be beautiful or scary.