Lets imagine you liked the game watch dogs that is generally focused around hacking. So you basically choose a game you like and recreate the main mechanic rom it and turn it into a game. Hope this helps.
You like a game, so use that game's idea example : assassin's creed = stealth and parkour so, u can make a game with stealth and parkour if u like assassin's creed Hope this helps If u don't understand, pls say your language and I will translate :)
