What are the factors most important to developing a game?

Question

I would like to know this to understand why some games like Mario is still playing today and because no other. This is to implement in future game projects.

What are the factors most important to developing a game?

Gameplay or Graphics? Both?

EDIT:

It's Possible combine these two?

Answer 1

Gameplay, combined with the often-missed concept of ease of play. If I can't pick up a game and make progress in a couple minutes I probably won't go back to it after I've been away. It's just disheartening to have to relearn how to play a game. Mario tended to have simple interfaces, one or two commands only, which makes it easy to come back to. Comes back to this: http://xkcd.com/484/

Answer 2

Gameplay. So many modern games just seem to spend their entire budget on developing an incredible graphics engine and forget to include plot / interesting gameplay. One example is Doom 3. It's kind of interesting, and spooky to play, but it's SO REPETITIVE. Tunnel after dark, deserted tunnel... compare it to Doom 2 which had a plethora of different types of missions. Doom 2 had crap graphics, but there's a reason people keep playing it.

That being said, a big reason people play old games is from nostalgic value. The gameplay might not be particularly excellent, but it does bring back memories, so that automatically adds value to the game.

Graphics are, of course, also important... you can't get away with 16-color 2D sprites anymore (or at least, not as easily). Rather than spend the entire budget on graphics, though, look into an OK graphics engine, and spend some time making the game:

• Fun to play.
• Have replay value.
• Easy to pick up.