3D game development includes scene rendering!
Every game is a sum of graphics, sound, music, scenario, design etc. You need it all, it needs to be made with good quality.
With your approach you should really go away from here, take unity, download some assets from store and make another crappy looking game.
Make a soup: just put some vegetables, meat and spices into pot of boiling water - this is you way.
My way is to carefully select every ingredient, use it in the right order, checking the taste from time to time.
Which soup will be more tasty?