I've gotten some work for the game engine going, so I thought I'd share a couple early videos of what there is so far. Don't be put off by the placeholder art, although it's lovingly crafted, it's not representative of what the final game will look like.
Here's the first video I posted, where you can see how the character jumps and interacts with terrain...there's still so much to be done to make it work, but it's a start.
This next video showcases the fact that the terrain is built on black boxes to indicate where the ground would be, which would have a graphical layer drawn over it. It also shows the game camera which follows the character to the middle of the screen, then scrolls the background until it hits an edge. This way the character will always feel like the center of attention.
All feedback is welcome, positive or negative.