Hey there, thanks for playing!
Believe it or not, having there be no separation in "modes" was the original plan, but we quickly realized it would be very difficult to place tiles underneath of you, especially when you're falling as fast as you are, so we went with the second best option, which is still a lot faster than most level creation tools that we could think of. We chose to represent the theme through the connection between the game world and the world of the debug mode and how we would represent that connection being cut off, not exclusively through the nature of how the debug world was implemented. Hope that makes sense.
And sorry about respawning inside the floor. We had to make some last minute performance and memory optimizations (which included not processing objects if they were out of range of the camera) and our team size and the time limit didn't allow us for rigorous playtesting with those new parameters.
But thanks for the feedback!