You can look at any game as the time line between Challenges & Choices as mentioned above,,
What is remaining now is to know the "ALL the types of Challenges available"
Because selecting the type of Challenges
will determine your game Genre 
Examples:
- If your Challenges are type of fighting ,, then you are designing an "Action Game"
- If your Challenges are type of solving puzzles ,, then you are designing an "Adventure Game"
However we will discuss the types of Challenges and the best way to combine them