7. Play the video game before it has begun development. That sounds crazy, but it can be done and it's an excellent way to get the plot down. To make this work, relax yourself and visually imagine that you're playing the game from start to finish. Let your mind suggest scenes, characters, plots, and strategies. Write down the game as its being played before your mind, and then repeat for each twist that you'd like to see implemented in the actual game.
8. Throw the plot into the mixer. There could probably be nothing more challenging in a video game than plot twists. As long as it's not too confusing to the point where players complain and quit playing, rearranging its plot could lend to some fun mind-bending twists that no one would ever predict. Try putting the game's beginning in the middle, or introduce all the subplots in the beginning of the game and have it all start to make sense toward the end (Think, "Pulp Fiction").
9. Look at the game with someone else's eyes. You may already know how you want your game to play, but so may everyone else. To inject some real creativity into your video game, design it as if it were presented from the eyes of a child, a lizard, or an inanimate object like a television. This exercise will not only keep the game intriguing for it's players, it will also keep its development challenging and interesting for you! Don't be surprised if your newfound view changes the game throughout its development. A new perspective has an interesting habit of creating new purposes and new solutions.
10. Challenge the rules. Try to remember that most advances in anything (not just video games) came about from challenging the rules. To make this work, think of the rules imposed on video game developers in the past and just break them! Do the opposite. Where they say you can't or you shouldn't - go on and do it. As long as your rule-breaking spree causes no harm and doesn't jeopardize the integrity of the game, try it!
11. Don't call your project a video game. Sometimes when you change the name of something, you start to view it differently. This is because different words move a line of thought into a different direction - a different direction that sparks new ideas.
12. Combine ideas. We're often told to ditch the first, second, or even third idea that we come up with for a project in favor for a much stronger idea. But instead of ditching these ideas, why not combined them into one. Combining ideas is one of the easiest ways to come up with new ideas and you can do the with your game. You could combine life forms, scenery, and all kinds of things. The end result would be nothing short of amazing and all the while, your players will wonder, "How did they come up with this stuff?!"