This will largely be nitpicks, because the game seems done and polishing is the only thing left.
- thanks for zipping it properly
- the "work in progress" screen feels like an insult to all the other submissions here with the state of the game that this is in
- always support WASD, even if the intended way is to play with a controller (you're already accepting space instead of enter)
- if the intended way to play is with a controller (suggested by the pre-start cutscene), then say it explicitly, so that I don't bother with the keyboard first
- you have an option for the "step sound", make the sound when I toggle it, so I know what is being switched to
- music is early gran turismo
- at the end of a level, show "next level" as the default option above level select
- the realistic backgrounds seem out of place if you focus on them
- not sure about this, but consider highlighting the target tile (option?) when you are about to do a 3D fall down
- the colors of the stage seem to hold no meaning (?) could be nice to be able to select what color to paint them if that's the case
- death seems like a heavy punishment that spikes instantly and you feel like shit, it would be nice to have a warning sign (say a yellow triangle) on all the dangers when you are 1 tile away from them to emphasise the danger, especially the tiny patrol spheres, which don't seem threatening at all other than for their color
Overall good job, feels like a AA PS2 game. Even thought it's not my type of thing with how "simple" it is, it has no real roadblocks that would have easily excuse dropping the game early. PGDG awaits.