The box is really slow. Like really, really slow. It's not my internet connection and it's not laggy because the gun thingy moves and responds just fine. Some of the ledges spawn too close together or too far apart, and some of them aren't anywhere close to goal. At least what looks like the goal, it has a trophy on it.
I can appreciate the simplicity, because it opens up to your imagination.
If you can fix the issues with the box jumping slow and the spawning locations for the ledges, and maybe even add a few power ups, you might have a winner here.