Time Game - Design, Challenges

Design
The game we're currently considering is an interesting puzzle/platformer where the player must travel forwards and backwards through time to be able to explore the world. The premise is that you're witnessing the end of the world, and you want to discover what's caused the apocalypse. Time around you is paused, but you have the ability to essentially "fast-forward" or "rewind" from where you are. The player is unable to move if the world is in motion, and is free to walk around when the rest of the world is frozen. In this way the player is isolated from everything and everyone else.

The main gameplay involves the fact that the positions of objects change over time. A simple example is that there might be a bunch of toppled rocks which disallow entrance to a building. The player can reverse time and find out that the rocks were the result of a landslide, and by reversing enough the entrance into the building will become unblocked.

A more interesting gameplay situation: There is an exploding car and the various windows, sheets of metal, engine parts, etc are all flying through the air. By pausing at the right time, the player can jump between the bits of the car to reach a higher ledge. A more morbic/comical example that we like to mention involves jumping between dead bodies being thrown from an exploding bus.

Challenges
There's a couple potential pitfalls here.
1. Differentiate this game from Braid or other time-based puzzle platformers. The gameplay would actually be quite different from these games; it's more about exploring in 3 dimensions (with the third being time) than finding a single solution to a puzzle. The fact that the player is independent from time is really what makes it different. But still, the obvious first reaction to this game is "that sounds like Braid!"

We can combat this in several ways. The most important is coming up with a tagline/pitch which makes it sound totally different - we should highlight the premise more than the puzzle mechanics. "Play with time!!" is old hat. The game is more about the exploration and isolation (at least to me.)

The next thing we should ensure is that we have an art style that goes along with this. If we decided to do a painterly whimsical art style, we'd be screwed. We need to come up with two or three cohesive but different styles, for when the world is frozen vs. when the world is playing forward/reverse.

Finally, we just need a solid story that presents the game as a unique work. We have many different ideas for this, and we'll be figuring this out soon.

2. Make sure the game mechanics stay interesting!
It's very difficult to tell, so far, if the game is going to be fun for more than 5 minutes. The puzzle/platform mechanic might work well for a while, or it might become easy and obvious quickly. We have many options for how to extend the mechanic or add new ones, but this is something we're going to have to figure out. The solution to this is testing and prototyping, over and over.

I guess those are the two main challenges for now. First real prototype coming soon.