The one critique I have is that the levels probably have too much unnecessary space. It's not fundamentally an issue but when combined with the slow-ish walk speed it gets a bit tedious, especially when the levels involve more back tracking.
Interesting, didn't realize the walking speed was slow. I actually have the reverse issue, it's too easy to over-walk. Maybe a cueing system were you could stab the arrow key 3 times to move 3 spaces? hard problem to solve, all solutions have tradeoffs.