Give me ideas for a basic and fun game

I am a new game developer, but i need to find a basic and a fun mechanics for my game.Waiting for your ideas, thanks.

What kind of game are you thinking? Puzzle games are pretty basic and can still be fun.

Start with im themed pimball, like avengers or minercraft!

Command and conquer red alert 2 yuris revenge, is a Simple strat game, and fun still

Garrys mod you can do anything literally as long as you can think about it

Hmm to start of at make a basic game where theirs npcs that come after and you gotta kill them with a gun a FPP

Play Garrys mod as you can do basically every thing

Bueno si te gustan los juegos de rol, puede ser Dofus

Just add a ragdoll system, something like the grappling hook from Just Cause

Milk Heals you if you pick it up. That's all I got. Also make a fun parkour system that is intuitive, but the milk idea is a tiny bit better.