Often times when game designers, programmers and artists want to make a game better they add something. They add more code, more detail and more features. The game gets bigger and 'better' with ever feature they add.
While the instinct is to add more features you can actually increase the creativity of your game by subtracting items. By limiting and taking away items or features you can increase the creativity of your game. For instance, if you have heard of the novel Gadsby, that entire novel was written without the letter E. That is a tough challenge especially because 'e' is a vowel. When you limit yourself you open your mind to creativity. You have to find creative ways to overcome this challenge.
So when you are designing your next game try and find something that is in every game and then take it away.